How to correctly set the current on a welding machine

How to cook correctly with an inverter welding machine

A welding inverter is equipment that helps to significantly simplify the work of a master and perform each stage of welding work with better quality. However, achieving such a result is only possible if the unit is used correctly. We will talk about this further.

Basic rules before using the inverter

Before operating the welding inverter, you must prepare place for welding, which will not be cluttered with unnecessary items and will allow you to carry out work without inconvenience.
You should not use such equipment in frost or high humidity without a canopy; you should also avoid placing the device in particularly dusty rooms and placing metal shavings or other debris near the workplace.
Pay attention to the technical capabilities of your device (on-duration coefficient - KP), such characteristics will help you find out how long it can work before overheating. This will also prevent wiring damage.
Time uninterrupted operation is calculated on the basis that with CP - 100% welding process at maximum current - 10 minutes.
As a rule, inverters are produced with a coefficient of performance of 60, 70%, which allows operation for 6-7 minutes. Remaining 3-4 min. – time for the apparatus to cool down, as well as a way to prevent deterioration in the health of the worker due to the heavier air associated with the operation of such equipment.
To avoid breakdowns, do not set tasks for the unit that are beyond its capabilities that do not correspond to its capacity.
The key to success when working with an inverter is current regulation and stable arc position . It is these factors that will help prevent the electrode from sticking and will allow you to create correct and neat seams.

Complete with a welding inverter, it is imperative to use auxiliary personal protective equipment:

jacket
gloves
mask with tinted glass

It is strictly forbidden to use masks with scratches on the glass or with a dirty filter.

This will ensure maximum safety for your activities.

You should also pay special attention to the choice of wires , which are connected to the main wire with a special clamp. The ability to transmit electric current in them varies from 200 to 500 A; for home use, as a rule, minimal ones are used, however, it is worth selecting them taking into account the thickness of the selected electrode and the strength of the current conducted.

Do not forget that before working with a welding inverter, it is necessary to check the quality of connections of all wires and their integrity.

Electrode holders must also be used as auxiliary equipment. These can be pliers or special welding holders.

Preparing to use a welding inverter

To successfully work with such equipment, you must follow the order of performing all actions:

Place the inverter on a work surface more than 2 m away from walls and other objects.
Check the grounding (in addition to the welding cable, the grounding cable must be connected similarly)
Select electrodes. Their size depends on the thickness of the material that needs to be welded (in everyday life, sizes of 2-5 mm are usually used)
Set the welding current . This parameter will be determined based on the thickness of the selected electrode and the density of the parts being welded.
However, if it is not enough to ignite the arc, the current can be increased, but this should be done very carefully to avoid sticking of the electrode.
Prepare the parts for welding (to do this, they need to be clamped in a vice or securely secured in another way.

Start the welding process

Insert the electrode into the holder
Attach the clamp to the part to be machined
Light the arc using touch (the principle is similar to lighting a match). Only it is better to hold the electrode at an angle at a distance of several millimeters after tapping once.
Move the lit arc, making slow forward movements, along the workpiece until an angle of 75 degrees is formed. In this case, it is better to concentrate your gaze not on the light formed by the arc, but to focus on the weld pool in order to monitor the welding process.
During welding, the main thing that must be observed is the distance between the electrode and the working metal (arc gap). The correct selection of such a gap allows you to keep the end at the same level throughout the entire process and ensures the creation of the necessary seams during the gradual combustion of the electrode.
After the workpiece has cooled, excess metal shavings on the formed welding seam must be removed with a hammer and then cleaned to a shine with a brush.

The result should be a beautiful and high-quality seam.

To help beginners

The success and fruitfulness of working with modern inverters for beginners is ensured by built-in automatic systems, these include:

Hot Start system solves the most common problem that most beginners face - the difficulty of igniting the arc for the first time.
Arc Force function helps prevent the electrode from sticking if it quickly approaches the workpiece by increasing the welding current.
If the electrode does get stuck, you can use the Anti-Stick function, which turns off the welding current and helps prevent overheating of the welding inverter.

Thus, the operation of a welding inverter will significantly facilitate the work of both professionals and smooth out typical mistakes of beginners, allowing them to make higher-quality products.
Such equipment is convenient to use and ensures the creation of welding seams close to ideal. To gain knowledge about the operating principles of such units, you can also watch this video:

Source: http://invertor.ksio.ru/praktika/kak-pravilno-varit-invertorom

Selecting welding mode: current, arc length, polarity

To get a high-quality and reliable welding seam, you need to understand which electrodes are best to use and which mode of manual arc welding to choose. In addition, it is important to take into account other equally significant factors, such as: the composition and thickness of the metal, the dimensions of the workpiece being welded, and for what purposes it will be used in the future.

In general, the welding mode is selected according to many factors and after analyzing the data obtained. In this article from the website mmasvarka.ru we will consider the main factors that, to one degree or another, can influence the choice of mode.

Welding mode selection

So, what factors influence the choice of one or another mode of manual arc welding. First of all, this is:

The main criteria when choosing a mode for MMA welding, of course, is determined by the burning nature of the welding arc, the stability of which depends on how correctly the current strength is selected for some specific electrodes. The higher the current, the larger the diameter of the electrodes you can weld thick metal. In simple words, high currents ensure better arc burning and good heating of the metal.

You should know that when a seam is applied vertically, the current strength changes less than when applied horizontally, by about 15%. For ceiling seams, the value of the welding current will be even less, by about 20%. Very often, values regarding the current strength are on the packaging with electrodes. In addition, you can determine what current strength to set on the welding machine from the table below with the values.

Average welding current (A):

Electrode diameter (1.6 mm) - electrode with rutile and basic coating (30-55 A) and (50-75 A);
Electrode diameter (2 mm) - electrode with rutile and basic coating (40-70 A) and (60-100 A);
Electrode diameter (2.5 mm) - electrode with rutile and basic coating (50-100 A) and (70-120 A);
Electrode diameter (3 mm) - electrode with rutile and basic coating (80-130 A) and (110-150 A);
Electrode diameter (4 mm) - electrode with rutile and basic coating (120-170 A) and (140-200 A);

In turn, in order to correctly determine the diameter of the electrode, it is necessary to take into account the thickness of the metal, the welding method and the geometric location of the seam. So, for example, for each electrode its own “own” current value is selected. If you greatly increase its performance, you can easily burn through the metal or, conversely, not achieve a high-quality and reliable weld.

Selecting current depending on the diameter of the electrodes

Thin metal, no more than 1 mm thick, is welded with 1 mm electrodes, and the current strength is set to the minimum possible values, in the range of 10-30 A. When welding thicker metal, up to 2 mm, electrodes of a slightly larger diameter are used, 1. 5 or 2 mm. The current strength for welding with these electrodes is set in the range of 30-50 A.

A 3 mm electrode is used to weld metal up to 4 mm, and the current on the inverter is set to 60-120 A. For welding metals over 10 mm thick, much thicker electrodes are already used - 4 and 5 mm. For their normal use, the welding machine must be set to a current of more than 120 A.

Welding arc length

To achieve a good connection, it is important to correctly determine not only the diameter of the welding electrodes, but also the length of the welding arc. There is a common belief among welders that the length of the arc should correspond to the diameter of the electrode used. However, it is very difficult for novice electric welders to maintain such a short arc without it being pulled to the side.

Therefore, when selecting this value, you should proceed from the current strength and diameter of the electrodes used for welding:

For electrodes up to 2 mm - the arc length is 2-2.5 mm;
For 3 mm electrodes, the arc length is 3.5 mm;
For 4 mm electrodes, the arc length is 4.5 mm;
For 5 mm electrodes, the arc length is maintained within 5.5 mm.

In addition, it is important to take into account the optimal welding speed, which also largely depends on the current strength and other features. Here you can follow one proven path, and with the correct selection of welding speed, the welding seam should be approximately twice the diameter of the electrode used.

Reverse or straight polarity?

To select the welding mode with a coated stick electrode, it is equally important to determine which operating mode to switch the welding inverter to. There are two of them, reverse and direct polarity.

In order to weld thin metal with an inverter and not burn it later, it is recommended to switch the welding machine to reverse polarity, when the flow of electrodes is directed not at the workpiece, but at the electrode. Conversely, if you connect the inverter in direct polarity, you can improve the quality of welding, for example, when you need to weld thick metal.

To connect the inverter in reverse polarity (for welding thin metal):

A positive terminal is connected to the holder with the electrode, and a negative terminal is connected to the workpiece.

To connect the inverter in direct polarity (for welding thick metals):

A negative terminal is connected to the holder with the electrode, and a positive terminal is connected to the workpiece.

To choose the right welding mode with an inverter, you need to take into account many different nuances. Only in this way will it be possible to achieve a high-quality and reliable welding joint that will withstand heavy loads.

Source: https://mmasvarka.ru/vybor-rezhima-svarki.html

How to quickly learn to weld with a welding inverter

You bought a welding machine and want to learn how to weld with an inverter for beginners.

There is no need to be afraid of difficulties! The inverter machine is easy to use; anyone without experience or knowledge can master the welding process in a short time.

Equipment, equipment, safety precautions

Safety precautions. Welding production is associated with electrical voltage, or in common parlance - current. The current is invisible, but can kill a person.

We check the welding cables for serviceability and connect them to the inverter equipment. Return cable with a clothespin on metal to the negative connector. Cable with electrode holder to connector +. We insert the electrode into the electrode holder.

When connecting the device to the network, visually evaluate the current-carrying cables for serviceability. After making sure that the cables are in good condition, we plug in the plug into the socket and the toggle switch on the device, having previously set the current regulator to the lowest value. If the cooling fan starts working smoothly, without crackling or noise, then everything is fine.

Metal weight. When connecting heavy structures, take precautions. If multi-ton products collapse, they can lead to death or disability.

Equipment. Welding production involves high temperatures. The welder must have:

canvas mittens (gaiters);
robe (special suit);
mask with a light filter;
respirator for work in confined spaces;
boots with rubber soles.

Gaiters are used when welding at heights, when arms are raised up, and mittens in other cases.

Other accessories:

welding machine;
hammer;
brush;
electrodes.

Electrodes are selected according to the metal (carbon content, additives) and diameter, depending on the thickness of the metal and the technical characteristics of the inverter.

Inverter Welding Basics

For beginners, experienced welders advise attaching the holder cable to the body, pressing it with the elbow of the arm and wrapping it along the forearm (from the elbow to the hand), and taking the holder in your hand. This way the shoulder joint will pull the cable, and the arm and hand will remain free.

The method will help you manipulate your hand with ease.

Correct placement of the cable on the forearm. You should not work with bare hands.

If you simply take the holder in your hand without wrapping the cable around your forearm, then during the welding process your hand will get tired and wrist movements will cause the cable to dangle. Which will affect the quality of the welded joint.

How to cook using inverter welding correctly? We set the welding current on the machine according to the diameter of the electrode, the type of connection and the welding position. Setup instructions are available on the device and the electrode pack. We take a stable stance, move our elbow away from the body (no pressing), put on a mask and begin the process.

For beginners, it is better to start welding with an inverter with metal workpieces larger than 20 cm.

It is known that a beginner, putting on a mask and lighting an arc, stops breathing, trying to boil the entire length of the workpiece in one breath. With short products, you will develop the habit of cooking in one go. Therefore, practice on long workpieces, learning to breathe properly when welding.

Workpieces (plates) on the work table can be placed in a horizontal plane - vertically towards you or horizontally, it makes no difference.

At the beginning of welding, place the electrode clamped in the holder at an angle of 90 degrees (perpendicular) and move it towards the seam by 30-45 degrees. Light the arc and start moving.

If welding is performed at an angle backwards, then the tilt of 30-45 degrees goes towards the seam.
If the connection occurs at an angle forward, then the electrode is tilted away from the seam.

The distance between the surface to be welded and the electrode is 2-3 mm, imagine that you are running a pencil along a sheet of paper.

Please note that when welding, the electrode decreases as it burns - gradually bring the melting rod closer to the surface at a distance of 2-3 mm and maintain an inclination angle of 30-45 degrees.

Watch a useful video on how to learn how to weld with electric welding for beginners:

How can a beginner learn to weld with a welding inverter?

First we learn to light and hold an arc. Feel the edge when to bring the electrode closer to the surface to be welded during combustion so that the arc does not interrupt.

The electrode is ignited in two ways:

tapping;
chirping.

The new electrode ignites easily. A slag film appears on the working rod, preventing ignition. You just need to tap longer to break the film.

To facilitate arc ignition, inverter devices have a built-in Hot Start function.
If a beginner quickly brings the electrode closer to the surface, the Arc Force function (arc force, anti-sticking) is activated, increasing the welding current, preventing the electrode from sticking.
If the melting rod gets stuck, the Anti Stick function cuts off the current, preventing the inverter from overheating.

What is arc force on a welding inverter and how to use it.

It is better for a beginner to first learn on a thread seam; the electrode is held smoothly, without oscillatory movements.

After mastering thread technology, proceed to welding metal with oscillatory movements. Which are used on thick metal for heating, holding the electrode at a certain point using movements - herringbone, zigzags, spiral or your own method.

Types of oscillatory movements

At the beginning of the connection, we carry out several movements from left to right, forming a weld pool and go along the seam making oscillatory movements. The angle of inclination of the electrode is 30-45 degrees. After passing, we beat off the slag with a hammer and clean it with a brush. Take care of your eyes, wear glasses.

Tip: at the end of the weld, make oscillatory movements to the sides and move the electrode towards the deposited metal. This trick will add beauty to the welded joint (get rid of the crater).

how to weld corner joints, butt joints and overlap joints.

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Seams are divided into:

single-pass (one pass replenishes the thickness of the metal);
multi-pass.

A single-pass weld is performed on metals up to 3 mm. Multi-pass seams are applied for large metal thicknesses.

Welders check the quality of the seam with a hammer - they strike next to the seam. If the seam is smooth, without irregularities, then after the impact the slag flies off completely, there is nothing for it to catch on. It is important to select the correct temperature regime: an overheated seam (hot) will break, an underheated one - there is a risk of lack of penetration.

The current is selected based on the diameter of the electrode, in theory 30 A per 1 mm of electrode diameter.

Direct and reverse polarity when welding with an inverter

Let's consider polarity when welding with an inverter. With a DC connection, the movement of electrons is constant, which reduces spattering of molten metal. The seam is of high quality and neat.

The device has a choice of polarity. What is polarity is the direction of movement of electrons depending on the connection of cables to equipment connectors.

Reverse polarity when welding with an inverter - minus on the workpiece, plus on the electrode. The current flows from minus to plus (from the workpiece to the electrode). The electrode heats up more. Used for welding thin metals, the risk of burn-through is reduced.
Straight polarity - minus on the electrode, plus on the workpiece. Current moves from the electrode to the workpiece. The metal heats up more than the electrode. Used for welding thick metals from 3 mm and cutting with an inverter.

The polarity is indicated on the pack of electrodes; these instructions will help you correctly connect the wires to the equipment.

Welding thin metal with an inverter

The essence of connecting thin plates comes down to selecting small-diameter electrodes and adjusting the welding current. For example, for metal with a thickness of 0.8 mm, electrodes with a diameter of 1.8 mm are used. The current on the inverter is set to 35 A.

Technology occurs in intermittent movements. Watch a video showing how to join thin plates in detail.

How to cut metal with a welding inverter

To properly burn a hole in a pipe, we set the current on the device to 140 A for a 2.5 mm electrode. We light the electrode, placing it in one place to warm up the metal and press it in. We move the electrode to a new place, warm it up and press it in. Gradually, we cut a hole in the pipe.

Pipe cutting

When cutting, it is better to place the plate vertically so that the molten snot flows down. If you cut in a horizontal position, icicles will harden at the bottom of the cut. That's all the tricks!

Beginners are tormented by the question, which polarity of wires is better when cutting with an inverter?

When cutting with electric welding, straight polarity is preferable. The melting zone is narrow but deep.
With reverse polarity, the melting zone is wide but shallow.

It is not recommended to cut with electric welding (metal melts from the cut zone). It’s better to take a grinder and cut off the desired piece.

Source: https://plavitmetall.ru/svarka/invertorom-dlya-nachinayushhix.html

How to set the welding current and choose the diameter of the electrode: rules, technique, features

How to work with welding current? What are the welding settings? All these questions and others will be discussed with you in this article.

Welding current - what is it? What is it for? Let's discuss these issues together. Welding current is the main parameter that describes the electrical properties of the welding arc.

It’s not easy for beginners to navigate all the settings the first time. The variety of GOST settings does not help beginners in any way. In order to correctly apply the welding current, all factors must be taken into account.

Here we will tell you everything about the correct use of welding current. In this article we will share our experience. A few years ago, workers had to do the calculations themselves.

Nowadays, everything has changed and you can use ready-made adjustments. This article will help you understand the types of welding work and device adjustments.

We will also talk about arc welding and settings for it. About how inverters are used and other questions.

Introduction

When performing welding work, you will need to take into account many parameters. You must understand what the welding mode consists of.

And that it will also consist of the strength of the current applied, and undoubtedly the diameter of the electrode. Pay attention to what current is used for welding (alternating or direct) - this is called the type of welding current.

Likewise, pay your immediate attention to the electrode, its brand, polarity, spatial position during welding, and layers of seams.

You need to understand what you will get at the end. Namely sizes, quality of seams and more. Correct adjustment will be very important in the work. Correctly configured mode, force during welding work.

So, let’s begin to understand how the current is selected correctly during welding.

Remember the main thing: the acceptability of the current depends on the definition of the electrode and its diameter in welding work. Of course, this is not one rule, these will be the basic skills for the upcoming work.

The selection of the electrode will also be very important. The thickness of the metal and the diameter of the electrode will be interdependent in relation to each other.

The thickness of the product (metal) will be equal to the diameter of the electrode used. It is also necessary to take into account that electrodes are also selected according to their intended purpose.

A good example would be if electrode welding is selected for the correct spatial position (horizontal, vertical, bottom, ceiling, etc.).

Unfortunately, not everyone can afford to purchase different types of electrodes for various seams.

Everything can be resolved. Example: You purchase electrodes, and they are designed for welding in the lower position, although you need to weld a vertical seam or a ceiling seam.

Answer: Ampere reduction is approximately 10-15%, in the second case by 20-30%. Be careful when welding the ceiling seam, the diameter should be 4 millimeters.

When using such settings, work with metal products will take place without burning. I think you already understand that there is always a relationship between the welding current and the size of the electrode diameter.

Current settings and electrode diameter

I think everyone has already understood that the diameter of the electrode directly comes from the thickness of the metal product. As was written above in the text. Thickness=diameter.

Example: when a worker must weld a part whose thickness will be from 2 millimeters to 8 millimeters, then electrodes with a diameter from 2.5 millimeters to 5 millimeters are selected.

This will be enough for your work. What about the current strength? The answer is on the surface.

When you do welding work on a metal product with an electrode diameter of 3.5 millimeters or more, the current strength will be 60 Amperes-100 Amperes. There is no need to be surprised by this difference.

You will choose the value yourself, it depends on the density of the metal product with which you are working. The most universal value would be 80 Amps. It is good for beginners.

When a worker applies a 4 mm diameter electrode, the current will be 120 Amperes - 200 Amperes. This is one of the common electrode diameters. This diameter can be used by welding experts and beginners.

If you want to use a semi-professional transformer (or a 5 mm electrode) for continuous operation and stable arc burning. Our recommendation would be to use 160 Amps - 200 Amps.

To work on professional equipment (or with a caliber of 8 millimeters), you need to apply a current strength of 250 to 345 Amps.

We draw your immediate attention to small inverter welding devices. They are available in any specialty store. Will appeal to professionals and amateurs.

But these devices have disadvantages. They use a small wire diameter, from approximately 2 millimeters. When using current from 40 Amps to 50 Amps.

Recommendation: When purchasing such models, make sure that the current supply in the device is smoothly regulated. Always follow the rules for setting the current strength. If there is a malfunction, the metal product will burn through rather than melt to the required depth.

The quality of the seams will depend on the correct adjustment. So read the regulatory legal acts, GOST. Accurate information = correct work.

conclusions

The final step when setting up the welding machine will be the strength of the welding current. No one is immune from mistakes. Sometimes intuition itself or automatic settings help when setting things up.

To avoid making mistakes, use tables with settings. But it’s better to memorize them. It will be easy. Experience will come with time.

You will independently adjust the inverter based on its errors. You will get good experience working with metal.

We will be waiting for your comments. Tell us your experience about the welding current settings and its relationship with the diameters of the electrodes.

Source: https://prosvarku.info/tehnika-svarki/kak-nastroit-svarochnyj-tok-i-vybrat-diametr-ehlektroda

How to cook using inverter welding with electrodes?

Welding is one of the affordable and reliable ways to firmly connect metal products. In a private house, in a garage or in a country house, there is always work related to welding: repairing a hole in a watering barrel, building a fence, repairing a metal table, and more.

Usually they turn to professionals, but if you need to do simple work and the beauty of the seam is not of great importance, then you can do the welding work yourself. It is better if the first lessons are taught by an experienced master, but in some cases you have to learn the basics of electric welding yourself.

The simplest, most accessible and popular is electric arc welding, which is why almost all craftsmen whose work is related to metal use it.

What is manual arc welding?

Fig.1

The manual arc welding process involves using an inverter or transformer to create an electric arc between the tip of the electrode and the surface of the metal. The elevated temperature melts the metal and electrode, promoting fusion of the materials. (Fig. 1) The place where the metal is connected to the electrode is called the weld pool. Standard bath sizes:

width 7-15 mm;
length 10-32 mm;
depth 5-6 mm.

The parameters of the weld pool are arbitrary and depend on various factors: welding mode, shape of the edges of the products being welded, speed of movement of the electrode, and others.

When the electrode melts, its coating forms a protective gas layer that prevents the metal from burning through and also protects it from exposure to oxygen. A weld seam is formed, covered with a layer of slag. The slag is subsequently removed using the welder's hammer.

Manual arc welding is very popular due to the advantages:

availability;
available supplies and equipment;
does not require re-adjustment of equipment for welding different materials;
good seam quality.

Tools and protective equipment for welding

For manual welding you will need: a welding machine, consumables in the form of electrodes, a metal brush, a hammer, a chisel and a mask with a light filter (welder mask).

If you have never seen an electrode holder and you are not even familiar with the general concepts and rules of electric welding, seek help from professionals. In the Enkor24 online store, experienced sales consultants will give competent advice and help you choose the necessary tools and equipment for both beginners and experienced welders. If you want to save your time and money, go to the Enkor24 online store.

ru, look, choose and buy only what you really need, without imposition or bias towards the brand, at very attractive prices.

Only here you will find a huge selection of welding equipment and can buy electrodes, welding machines, welder’s masks, leggings, presented by both leading Russian and foreign manufacturers: ESAB, Elitech, RESANTA, Enkor, Fubag, Plasmatec, TIGARBO, LEZ, Telwin and others .

Source: https://svarkagid.com/kak-pravilno-varit-invertornoj-svarkoj-s-elektrodami/

How to choose the current for welding with an inverter

Carrying out manual welding using an inverter is gaining increasing popularity among home craftsmen, due to the wide offer of various models with different price ranges.

To connect iron products using inverter welding, a minimum of equipment is required, characterized by its versatility along with low energy consumption and compact dimensions, which further attracts the attention of inexperienced craftsmen.

Learning inverter welding technology for beginners will not be the slightest difficulty.

Operating principle of a welding inverter

A welding inverter is a powerful power supply, which in terms of energy conversion is similar to a switching power supply.

The main stages of energy conversion in the inverter:

Reception and rectification of network current with a voltage of 220 V and a frequency of 50 Hz.
Converting the resulting rectified current into alternating current with a high frequency from 20 to 50 kHz.
Stepping down and rectifying high frequency alternating current into currents ranging from 100 to 200 A and voltages from 70 to 90 V.

Converting high-frequency electric current to a current of the required value allows you to get away from the inconvenient dimensions and heavy weight of the inverter, which are found in conventional transformer devices, in which the current value is achieved by converting the EMF in an induction coil.

Also, when the welding inverter is connected to the network, there will be no sharp jumps in electrical energy, and moreover, the device contains in its circuit special storage capacitors that protect the machine when welding during an unexpected power outage and allow the inverter arc to be ignited more gently.

Obtaining a high-quality weld when welding depends on many factors, therefore, before starting work, the master must familiarize himself with how to properly use the inverter according to the attached instructions, as well as the basic rules and nuances of performing welding work, which will be described in detail below.

Particular attention should be paid to the diameter of the welding electrodes. It is important to know that the amount of energy consumed directly depends on the thickness of the welding rods, and, accordingly, the larger their diameter, the higher the energy consumption.

This information will help to correctly calculate the maximum electrical energy consumption of the inverter, which will prevent adverse consequences from its operation as reflected on household appliances.

There is also a dependence of the diameter of the electrode on the current selected for the work, a decrease in which will lead to deterioration in the quality of the seam, and an increase - to an excessive combustion rate of the welded rod.

Inverter design for welding

In order to understand how to properly use a welding machine, a novice master should familiarize himself with the design of the inverter.

The welding inverter is a metal box with internal components, a total weight of about 7 kg, which is equipped with a handle and a shoulder strap for ease of carrying. The housing of the welding inverter may contain ventilation holes that promote better air outflow when cooling the unit.

The front panel has buttons for switching the operating state, knobs for selecting the required voltage and current, outputs for connecting work cables, as well as indicators indicating the presence of power and overheating of the inverter during welding.

The cable for connecting the device to the power supply is usually connected to the connector located on the back of the inverter.

When the electrode comes into contact with the metal plates being welded during welding, a high-temperature arc is formed, as a result of which both the elements of the welded rod and the metal of the welded joint melt. The bath formed in the arc area by the molten metals of the plates and electrode is protected from oxidation by a liquefied coating of the electrode.

After complete cooling of the metal, the upper surface of the seam, protected by electrode coating during welding, will turn into hardened slag, which can be easily removed by light mechanical action (for example, tapping). It is important to maintain the same distance-gap between the metal of the welded joint and the electrode (arc length), which will prevent its extinction.

To do this, the supply of the electrode to the fusion area must be carried out at a constant speed, and the guidance of the welding rod along the weld joint must be smooth.

Safety precautions

Before starting home welding, the electric welder needs to take care of safety precautions:

wear a protective suit made of durable, high-density natural fabric that is not subject to fire and melting when sparks hit it. The suit should cover the neck area and have sleeves that fasten tightly at the wrist.
protect your hands with mittens made of rough fabric;
wear comfortable leather shoes with thick soles;
Protect your eyes with a welder's mask with a light filter that depends on the current strength during welding.

The place where welding will be carried out must also be carefully prepared:

a wooden flooring has been laid, which performs a protective function against possible electric shock;
the welding site is cleared of anything unnecessary (to prevent welding splashes);
lighting must be of high quality;
The welder's movements should not be constrained.

Basics of welding with an inverter

Learning to weld with a welding inverter is not difficult. The very first stage of mastering welding techniques will be preparing the metal plates to be welded:

cleaning the edges of the plates from traces of corrosion with a wire brush;
degreasing the edge with a solvent.

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Relying on the diameter of the electrodes, the choice of which is based on the grade of the metal being welded, it is necessary to select the current value for welding. The value of the welding current will also be determined by the cross-section of the elements being welded. To ensure that the quality of the seam is not affected when welding with an inverter, the pre-welded rods should be dried in an oven with a heating temperature of 200 º for 2-3 hours.

In order to weld metal, the ground terminal must be connected to the plane of the element being welded. Next you need to ignite the arc. You can do this in two ways:

striking the metal surface of the plate, similar to igniting a match head;
tapping the electrode on the surface to be welded.

Working with a welding inverter will be more convenient if, when welding, the holder cable is pressed to the body, having first wrapped it around the forearm of the working hand. In this position, the cable will not pull towards the holders and adjusting its position will be more convenient. Therefore, when choosing an inverter, special attention must be paid to the length and flexibility of the cables, because the convenience of the welder will depend on these indicators.

After igniting the arc, the electrode must be moved away from the plane of the metal plate to a distance equal to the length of the arc (approximately 2-3 mm) and welding can begin. To make high-quality welding, you must constantly monitor the length of the electric arc. A short arc (about 1 mm) can cause a welding defect called “undercut.”

This welding defect is characterized by the appearance of a shallow groove parallel to the weld, leading to a decrease in the strength of the weld. A long arc is unstable, provides a lower temperature in the welding zone, and, as a result, such a seam has too small a depth and is “smeared”.

A welder who knows how to properly adjust the arc length will receive a high-quality weld.

After welding is completed, you should carefully beat off the scale that has frozen on top of the seam with a hammer.

Polarity when welding with an inverter

Melting of the metal is caused by exposure to the high temperature of the welding arc, which occurs as a result of connecting the opposite terminals of the inverter to the metal plate and to the welding rod. Depending on the order of connecting the welding inverter terminals, a distinction is made between direct and reverse polarity.

Polarity is the setting of the direction of electron movement. Both direct and reverse polarity are used when welding with an inverter, so it is important for a novice welder to know the differences between these types of connections.

Straight polarity is the polarity that occurs after connecting the electrode to the minus terminal and the metal plate to the plus terminal. With this connection, the current flows from the electrode to the metal, as a result of which the metal heats up more intensely, and the melting zone becomes sharply limited and deep. The direct polarity of connecting the welding inverter is selected when welding thick-walled elements and when inverter cutting.

Reverse polarity is characterized by connecting the “minus” to the metal plate, and the “plus” to the electrode. The fusion zone with this connection is wider and has a shallow depth. The direction of current is directed from the metal workpiece to the electrode, resulting in greater heating of the electrode. This procedure reduces the risk of burn-through and is used when welding thin-walled metal products.

Working with thin metal

Welding of thin-walled metal products with an inverter is carried out by connecting the terminals according to a circuit corresponding to reverse polarity and placing the electrode at an angle forward. This welding technique provides a smaller heating zone with sufficient seam width.

Ignition of the electrode should be done extremely carefully, because the beginning of the pool when welding thin metal is often accompanied by a burn-through. Welding thin metal with an inverter must be carried out gradually, welding small areas with a short-term removal of the electrode from the bath. At this moment, you need to make sure that the yellow glow of the electrode tip does not go out.

The quality of the weld directly depends on the quality of the electrodes, which will help avoid excessive formation of slag in a small-section weld. Also, the use of small-diameter electrodes avoids burning through the metal.

When completing a weld, you should not abruptly tear off the electrode to extinguish the arc, because in this case a noticeable crater will form at the end of the seam, which will worsen the strength of the metal of the welded joint and the result of the welding equipment will be unsatisfactory.

Another defect that often occurs when welding thin metal is deformation of the product. To prevent its occurrence, it is necessary to carefully secure the parts being welded before welding.

Tips for novice welders

A welder with little experience often wonders how to properly weld metal using electric welding. General tips for working with an inverter and rules for welding metal with an electrode will be given in the section below.

When welding metal with an inverter, you must carefully monitor that the weld is flush with the metal. An electric arc penetrating the metal with intense speed and sufficient depth causes the pool to move backward and creates a weld that can become defective if the speed of the electrode is too high. An ideal seam will be obtained if the electrode performs zigzag and circular vibrations.

When changing the direction of movement of the electrode, remember that the bath follows the heat. The formation of an undercut occurs against the background of insufficient metal of the electrode, so it is worth strictly monitoring and controlling the boundaries of the bath.

By placing the electrode at a certain angle, you can control the direction of movement of the bath, while the vertical position of the electrode will contribute to sufficient penetration. The bathtub in this position will be pressed down and have good boundaries, and the seam will have less convexity. Too much tilt of the electrode will not allow you to control the bath.

Inverter welding is also applicable when performing pipe welding work. Welding takes place under rather difficult conditions, so it is necessary to pay great attention to the quality of penetration at rotary joints. An angle of 30º is the standard angle of inclination of the electrode to the pipe surface.

On pipes made of low-alloy steels with a wall cross-section up to 12 mm, the seam will be single-layer. For pipes with a larger wall thickness, a second weld should be applied, which will increase the overall strength of the weld. After each new weld, it is imperative to clean the hardened slag.

Pipes with a diameter of up to 0.5 m must be boiled continuously.

An inverter is a simple welding machine that is ideal for a novice welder to carry out welding work at home. When choosing an inverter, you must rely on your own needs and the compliance of the selected device with them, thus meeting your needs.

Source: https://www.novaso.ru/svarka/kak-podobrat-tok-dlya-svarki-invertorom.html

Alloys of non-ferrous metals, their composition and application - Metals, equipment, instructions

Copper, nickel, lead, zinc and tin are called heavy metals. This name arose during the period of industrialization of the country in connection with the concept of “heavy industry” and its significance for the development of the national economy. At the same time, this name successfully distinguishes heavy metals from the equally important aluminum and other light metals that have a lower density.

The conditional boundary between heavy and light metals is considered to be a density of 5000 kg/m3. In foreign languages there are no similar names that summarize these groups of metals; however, their importance in technology is everywhere recognized as paramount after iron.

Iron has long been the main material for building structures, mechanical engineering and transport. However, already in the 19th century. With the development of new industries and technology, some of its shortcomings came to light.

Of course, we are not talking about pure iron, but about its industrial alloys - cast iron and steel.

Possessing a wide variety of valuable properties, ordinary cast iron and steel are at the same time insufficiently resistant to corrosion in air and especially under the influence of water, solutions of salts and acids, have little thermal conductivity, little electrical conductivity and have a fairly high coefficient of friction.

Heavy non-ferrous metals and their alloys have been used since the beginning of the 19th century. became iron substitutes in those industries that required special properties that were not sufficiently expressed in cast irons and steels.

Copper

Copper has high electrical and thermal conductivity. In terms of these properties, it is second only to silver. The ductility of copper allows it to be easily processed by rolling, stamping and drawing. With the development of electrical engineering, copper has become the main material for wires, busbars, contacts and other conductive products.

The high thermal conductivity of copper allows it to be used in all kinds of devices that conduct heat - in heaters and refrigerators. In the chemical industry, copper is used to make coils for heating or cooling solutions, digesters, pipelines and other equipment parts.

Even small impurities of other elements greatly reduce the electrical conductivity, thermal conductivity and corrosion resistance of copper. To fully utilize these properties, a metal containing no more than 0.05% impurities is required.

However, pure copper is too soft for building structures, machine parts and fittings. Its alloys with other metals have significantly greater strength and hardness, many of them are superior to copper in other valuable properties, for example, corrosion and anti-friction.

Copper alloys with 10–40% Zn - brass is cheaper than pure copper. At the same time, they are well processed by pressure and cutting, are more durable, hard and resistant to corrosion.

Small additions of iron, aluminum and manganese in various combinations give brass even greater strength and hardness, and additives of tin, aluminum, manganese and nickel enhance anti-friction properties.

In the form of sheets, rods, pipes and various castings, brass is widely used in chemical and general engineering, shipbuilding and military equipment.

Previously, only copper alloys with 6–20% Sn, known for their high mechanical properties, corrosion resistance and antifriction, were called bronzes. Later, due to the scarcity of tin, they learned to produce similar alloys by adding other metals to copper.

Now, in addition to tin bronzes, aluminum (5–11)% Al, lead (25–33)% Pb, silicon (4–5)% Si, beryllium (1.8–2.3)% Be, cadmium bronzes are widely used up to 1% Cd, etc.

All of these alloys contain small amounts of secondary alloying components that enhance certain properties of copper.

Each type of bronze is valuable in its field of application: aluminum bronzes with lead additives are needed for bearings, and beryllium bronzes are used for the manufacture of springs.

Brasses and bronzes, like many other alloys, are divided into cast and wrought, suitable for casting or for processing by pressure, rolling, forging, stamping, drawing.

Copper-nickel and copper-nickel-zinc alloys: cupronickel (5–35% Ni) and nickel silver (5–30% Ni and 13–45% Zn) are especially resistant in aggressive environments containing active chemicals. In the form of tape, sheets and wire, these alloys are used for the manufacture of medical instruments, precision mechanics products, cutlery, household and artistic products.

Copper has been known since ancient times - the Bronze Age was a period of rapid development of material culture. Subsequently, bronze was replaced by cheaper and more accessible iron. With the emergence of large-scale industry, copper production and consumption began to increase rapidly again.

Until 1958, copper occupied the first place among non-ferrous metals in terms of global production. Now it is inferior to aluminum in this regard, but still remains a scarce metal that requires substitutes. In electrical engineering, some copper began to be replaced with aluminum - less electrically conductive, but lighter.

This is beneficial: the consumption of aluminum by weight is almost half that of copper. In railway transport, copper and bronze are partially replaced by zinc alloys. In military technology, cartridge cases began to be made of steel instead of brass and they were only covered with a layer of brass - clad.

Replacing copper with other, less scarce metals and alloys is an important problem of our time.

Nickel

Compared to other heavy non-ferrous metals, nickel is the most durable, hard, refractory and resistant to corrosion. Like iron and cobalt, it is ferromagnetic. Pure nickel is ductile and easy to process.

Nickel is relatively expensive, and its consumption in pure form is low. To protect against corrosion and for decorative purposes, products made of iron, aluminum, magnesium, zinc and other metals are coated with a thin layer of nickel (nickel plating). In the form of sheets, pipes, and wire, it is used for special products for chemical production - parts of equipment and devices.

Nickel is also required for the production of alkaline batteries - iron-nickel and nickel-cadmium. These batteries are lighter, more compact and more reliable in operation than lead batteries. Nickel catalysts are used in many chemical technology industries.

More than half of all nickel is consumed in alloys with iron.

Strong and wear-resistant nickel cast irons containing chromium, molybdenum and copper are needed for the production of powerful internal combustion engines for locomotives, special machines and dies.

Many nickel alloys are heat-resistant: they do not oxidize in air at high temperatures. These include alloys EI, Inconel, Nimonic, Gastelloy, etc., capable of operating at temperatures up to 600 °C. They are used for the production of jet turbines, gas turbine units and in nuclear reactors.

Nichrome (75–85% Ni, 10–20% Cr, the rest iron) and other similar thermoelectric nickel alloys are not only heat-resistant, but also have high ohmic resistance and are used for wire or tape heaters.

A highly magnetic alloy of nickel with iron (permalloy) and other alloys similar to it are used in electrical engineering and radio engineering.

Of the alloys of nickel with non-ferrous metals, copper-nickel alloys are the most important; they have already been discussed above.

The first metallic nickel was obtained in Sweden in 1751, and its production for sale began only in 1825. For a long time it remained insignificant. Many of the valuable properties of nickel were not known until the beginning of the 20th century, so it was only in the 20th century that the demand for this metal began to grow rapidly.

Now nickel consumption in all countries is strictly taken into account and measures are taken to use it economically. To achieve this, more and more of the nickel in stainless steels is being replaced by chromium, and conventional steels are being coated with a thin layer of stainless steel (cladding).

Lead

Lead has been known since ancient times - at least two millennia BC. e. At that time, the easy machinability of soft lead and its high density were especially valued. Coins, jewelry, various vessels, water pipes, projectiles for slings and catapults were made from lead. With the invention of gunpowder, lead was used to make buckshot, bullets and shot.

Lead's resistance to dilute sulfuric and hydrochloric acids and many other reagents made this metal a popular choice in the 19th century. the main material of the then emerging chemical industry. Lead is easily rolled. Sheet (rolled) lead with a thickness of 2 to 10 mm is convenient for covering equipment and protecting it from corrosion.

The sheaths of cables intended for long-term operation underground, in water or in a humid atmosphere are now made from lead, adding small amounts of other metals to it for greater ductility.

Lead-acid batteries are still needed to ignite internal combustion engines, despite the advent of nickel batteries, which are significantly more expensive. About half of all lead is spent on the production of cables and batteries.

In nuclear technology, lead serves as protection against γ rays, which it absorbs better than many other materials.

In military affairs, lead is still needed for the manufacture of shrapnel and core bullets.

Lead alloys differ from pure metal either in greater strength and hardness, or in anti-friction; Most of them are also resistant to corrosion.

Alloys with a low coefficient of friction - babbitts (after the name of the inventor Babbitt) - are divided into tin-bearing and tin-free. The former contain, in addition to lead, tin, copper, antimony, cadmium, nickel and tellurium, and the latter contain sodium, calcium, tellurium and other elements. Babbitts are low-melting, they are poured in liquid form into bearing shells or applied as a layer on a steel strip.

In the chemical industry, alloys of lead and antimony are often used - they are hard and resistant to corrosion.

In alloys for soldering - solders, lead is partially replaced by more expensive and scarce tin.

Demand for lead constantly outstrips its production. Therefore, in modern industry, new ways to save lead are being outlined. They are now trying to replace the lead sheaths of some cables with plastic ones, and anti-corrosion coatings with synthetic organic materials. Printing lead alloys can sometimes be replaced with zinc alloys, and in the future - with plastics, when plastics with good casting properties are obtained.

Zinc

Information about the history of the development of zinc production is varied. According to some of them, this metal was produced in India and China back in the 5th century. Industrial production of zinc in Europe arose only in the 18th century. in England, then in Upper Silesia.

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Currently, about half of the zinc produced is used to coat iron to protect it from corrosion. A thin layer of zinc is applied to the iron using a hot method or electrolysis.

The electrolytic coating is thinner and zinc is consumed more economically; however, due to more complex equipment, hot-dip galvanizing is still used more often than electrolysis. Zinc reliably protects iron from corrosion in air and cold water.

Galvanizing is much cheaper than coating with tin - tinning or nickel - nickel plating.

Another important area of zinc consumption is the production of alloys, including the already familiar brass and nickel silver.

https://www.youtube.com/watch?v=PFhXTomXXSw

Zinc-based alloys partially replace bronze and babbitt in bearings. These zinc alloys contain 8–11% aluminum, 1–2% copper, and 0.03–0.06% magnesium. The same components, but in different proportions with zinc, are contained in typographic alloys, similar in properties to lead-antimony alloys.

Compared to other non-ferrous metals, zinc is cheap, and its resources in known deposits are quite large. Therefore, the problem of replacing zinc with other metals did not arise. With the increase in aluminum production and a decrease in its cost, it may be advantageous to coat iron not with zinc, but with aluminum - aluminizing.

Source: https://spb-metalloobrabotka.com/kak-pravilno-vybrat-tok-pri-svarke-invertorom/

Features of inverter aluminum welding: what should the inverter be like? Selection of electrodes, process technology

Features of aluminum are as follows:

This metal is characterized by the fact that it does not change its color when heated , which complicates the process of monitoring the state of the weld pool;
there is a need to clean the oxidized area with an abrasive , since the film formed from aluminum oxide reduces the possibilities for processing and welding;
Don't rush when working with aluminum . This metal must be provided with the necessary degree of heating;
excessive overheating is also unacceptable, as it leads to deformation of the product . Using the attachment improves the quality of work and ease of control. The attachment is an addition to the main welding inverter and is directly connected to it. Usually not included in the kit, but purchased additionally. Helps to better control the process and obtain a better and more even connection.

Rules for welding aluminum with an inverter

There are a number of rules for obtaining a high-quality result when welding aluminum with an inverter:

For optimal process, it is recommended to use tungsten electrodes . In this case, special attention should be paid to the size of the tip and the composition of the electrode, since these factors affect the quality of the connections made.
Preheating aluminum parts will reduce the consequences of deformation in the weld area from exposure to high temperatures . In this case, the heating temperature is directly proportional to the size of the parts being welded. If the structure is large, then only the local welding area can be heated.
It is necessary to weld aluminum elements under the protection of inert gases (argon, argon + helium);
Welding manipulations when working with aluminum are carried out only using reverse polarity current . This choice is due to the possibility of destroying the resulting oxide film by cathode sputtering.

Which electrodes are best for welding aluminum?

Approximate cost of tungsten electrodes on Yandex.market

The greater the thickness of the parts, the larger the diameter of the electrode. An incorrectly selected size will result in either a weak connection or defects in execution.

Inverter for welding

Inverters used for welding aluminum parts may differ in design and modification. The most common are semi-automatic devices, as well as electric arc installations.

The machine selected for welding aluminum parts must have the following capabilities:

an oscillator must be installed to provide the possibility of increasing the starting current;
adjustment of the main current with high accuracy in accordance with the thickness of the part;
inert gas supply regulator for welding operations.

Approximate cost of inverters for welding on Yandex.market

What parameters are set depending on the thickness of the metal being welded?

When setting up the welding machine, you must perform the following manipulations:

adjust the AC balance (plus or minus) . Typically, when welding aluminum, reverse polarity is used, that is, “-“;
adjust the welding current depending on the thickness of the elements being connected . The pulse current increases with increasing thickness of the parts being welded. So, for aluminum with a thickness of 1 mm, a current of 23 to 27 Amperes is used, and for welding aluminum with a thickness of 5 mm - 150-180 Amperes;
adjust arc attenuation, which also depends on the thickness of the parts : the thicker, the longer. For example, to connect aluminum with a thickness of 2 mm, it is enough to set this parameter for 3 seconds;
set up gas purging for cooling (if such a function is available).

Welding technology

Any welding work, in addition to the process itself, has certain stages of preparation:

cleaning the surfaces to be welded and degreasing them . To ensure a high-quality connection, the elements are cleaned of fats, oils, dust and dirt. After this, the elements are degreased with acetone or another suitable solvent;
If necessary, the edges of the parts to be welded are cut . If the connection elements are up to 4 mm thick, then cutting is not performed. When connecting parts with coated electrodes, cutting is allowed only when the thickness of the parts is over 20 mm. For thin parts, flanging is most common;
Be sure to remove the aluminum oxide film with some kind of abrasive or wire brush;
adjust equipment for a specific product based on its composition, size and thickness (set starting and welding currents, arc decay time, adjust alternating current balance, adjust gas purge).

Carry out the necessary manipulations in accordance with the specified parameters and compliance with all standards:

arc ignition - contact (the arc occurs as a result of the electrode being shorted to the product) or non-contact (the arc is caused by an oscilloscope discharge) method;
The welding process must be carried out so that the angle between the filler wire and the torch is equal to 900 . The wire feed should be carried out in short reciprocating movements. Transverse vibrations of the electrode should not be allowed;
thin aluminum up to 4 mm thick is welded in one pass , to connect sheets with a thickness of 4-5 mm, double-sided welding is used, and with a thickness of 6 to 12 mm, the edges of the sheets are prepared by cutting type “V” or “X”;
gas supply begins five seconds before the arc ignites and ends seven seconds after the end of welding;
the smaller the weld pool, the lower the likelihood of oxidation of the edges of aluminum parts will be;
the electrode should be as close as possible to the surface and be in interaction with the gas.

All work is carried out carefully and without haste, with careful metal penetration and compliance with safety regulations.

https://www.youtube.com/watch?v=ZlOj3ebCsbw

At the end of the process, cool the product and tool, evaluate the quality of the work performed.

( 1 rating, average 5 out of 5 )

Source: https://elsvarkin.ru/texnologiya/invertornay-svarka-alyuminiya/

How to cook with a welding inverter: nuances of the process

Inverters are the best welding machines. You should know that old transformers are heavy and difficult to use. Anyone can operate the inverter. To do this, you just need to know the basic principles of welding metal with this device.

The inverter welding machine is lightweight and has high power, which allows even a novice welder to carry out complex welding work.

First of all, the advantages of an inverter welding machine are its light weight and great capabilities. Thanks to this, with the help of this device it is possible to perform work that was previously performed only by complex devices. The electrical energy that is consumed by this small device will be directed only to the operation of the arc, with the help of which the welding process itself is carried out.

How to learn to weld metal, what do you need to know before performing the welding process?

Table of correspondence between electrode diameter and welding current.

An inverter for welding is an economical device that is convenient to use. Even beginners can learn to weld metal with it. Before welding, it is important to learn about the operating principle of this device. The inverter is an electronic welding machine, so the main load will fall on the electrical network.

When old welding machines are plugged in, there is a strong and maximum possible jolt of electrical energy. In connection with this, the power grid of the entire area is switched off. The inverter has storage capacitors that are capable of storing electrical energy, as a result of which uninterrupted operation of the electrical network can be ensured.

In this case, the electric arc of the device will ignite softly.

You should know that the larger the diameter of the electrodes, the more electrical energy it uses. Therefore, if you want to check the welding machine in operation, you will need to calculate how much electrical energy the device will approximately consume. This is necessary in order not to burn your neighbors' household appliances.

For each electrode diameter, the minimum current strength is shown. Therefore, if you want to reduce the current, you won’t be able to make a seam. If you want to experiment and increase the current, you can make a seam, but the electrode will burn out quite quickly, as a result of which the work will not be comfortable.

Before welding, it is recommended to place a bucket of water in the room. You will need to prepare the workplace and all the elements that are planned to be welded.

To be able to correctly install the metal workpieces to be welded, clamps or a vice should be used.

How to properly weld metal with an inverter?

The process of arc initiation and combustion pattern.

First of all, you will need to know what elements will be needed for protection when working with a welding inverter. You need to buy the following:

Leather gloves.
Helmet for protection.
Jacket made of thick fabric.
Metal brush.

You will need to adjust the welding current and select an electrode. In order to weld with a welding inverter, you will need to use electrodes from 2 to 6 mm. The welding current is set depending on the thickness of the machine elements and the material being welded. In most cases, there is information on the device body about what current strength should be. There is no need to bring the electrode to the welding base quickly. If you do this, sticking may occur.

Next, the ground terminal is connected to the base, which is welded.

The welding process must begin with ignition of the arc. You should bring the electrode at a slight angle to the part that is being welded, and then touch it to the welding base several times so that you can use the electrode for welding. The electrode is held several elements away from the workpiece that is being welded. In most cases, this distance is equal to the diameter of the existing electrode.

The result will be a weld seam. Scale (metal scale at the top of the weld) is removed with a small hammer. You can also use any other durable object that has a lot of weight.

How to control the arc gap?

Figure 1. An arc space of suitable dimensions will help form a good seam.

The arc gap is the gap that appears during welding between the metal workpiece and the electrode. It is important to continuously monitor and maintain the same value of this gap.

If there is a small gap, this can lead to the seam being convex and not fused on the sides due to the fact that the base metal will not be able to warm up quickly.
If there is a large gap, then it will not be possible to weld the part, and the arc will jump. As a result, the metal that is melting will fit crookedly.
It is important to provide the required gap. This is necessary in order to be able to form a normal seam with good penetration. Visually, a gap of suitable dimensions can be seen in Fig. 1.

If you learn to control the arc length, you will be able to get the optimal result. The arc will pass through the gap and melt the base metal. As a result, a weld pool is formed. The arc will also be able to ensure the transfer of the metal that is being melted into the bath.

How to make a welding seam with an inverter correctly?

Figure 2: Straight polarity creates a narrow and deep melt zone.

If the electrode moves quickly during welding, you will end up with a defective seam. The bath line is located lower than the base of the base metal. If the arc penetrates quickly and deeply into the base metal, it can push the bath back, resulting in a weld. During welding, it is necessary to ensure that the seam is located at the level of the metal.

You can make a perfect seam by using arcing and zigzag movements. While performing circular movements, you will need to control the level of the seam, placing the bath evenly in a circle.

In the process of movements in different directions, the same seam will form, so you need to control the appearance of the seam during welding, first of all from one edge, then in the upper part of the bath, and finally on the other side, and so on.

The pool will follow the heat - this is important to remember when changing direction during the welding process. Undercutting will occur when there is not enough electrode metal to completely fill the bath during lateral movements. In order to prevent the appearance of such a side groove, you will need to control the outer boundaries and regularly monitor the bathtub. If necessary, you can make it thinner.

To manipulate the bathtub, you need to apply the force of the arc, which is located at the end of the electrode. During the process of tilting the electrode, the bath will push, but will not be pulled. Consequently, the more vertical position the electrode takes during welding, the less convex the seam will be. When the electrode is placed in a vertical position, all the heat will be concentrated under it and the bath will be pressed down, melt well and spread around.

When the electrode tilts slightly, all the force will be directed backwards, causing the seam to rise (float).

When the electrode tilts too much during welding, the force will be applied in the direction of the seam, and this will not allow full control of the bath.

If you need to make a flat seam or move the bath back, you should use the electrode at different angles.

Work should begin from 45° to 90°, because such angles make it possible to observe the bath and weld with ease.

What you need to know about forward and reverse polarity?

Figure 3. With reverse polarity, the melting zone will be wide and not deep.

In the case of direct polarity, there will be a reduced heat input into the workpiece, the melting zone will be narrow and deep. Visually the process can be seen in Fig. 2.

In the case of reverse polarity, there will be a reduced heat input into the workpiece, the melting zone will be wide, but its depth will be small. It is possible to obtain the effect of cleaning the base that is being welded with cathodes. Visually the process can be seen in Fig. 3.

How to cook thin metal sheets with an inverter?

It is worth paying attention to the polarity of the electrodes. During DC welding, there will be a negative and a positive charge. First of all, you will need to determine which charge needs to be connected to which place. You need to proceed from the fact that a positive charge, holding the material that is being welded, will be able to heat up more.

Most often, reverse polarity in the welding process is used when it is necessary to weld thin metal with a welding inverter, which can be easily burned. Therefore, it is important to ensure that the polarity is reversed and the amperage is correct.

Electrodes for welding thin sheets of metal must be connected with the “plus” to the arc of the device, and the “minus” to the sheet of metal.

If you need to ensure that the weld seam on a sheet of metal is of the highest quality, and there are no holes on the sheets, you will need to ensure that the seam is visible during the welding process.

This means that the angle of inclination of the electrode relative to the workpiece should be approximately 30°. The electrode will need to be placed as close as possible to the metal being welded.

After this, you need to wait until a red spot begins to form, under which a drop of metal appears, capable of connecting the sheets to be welded together.

As the electrode slowly moves along the base of the metal sheets, the resulting drops will connect the workpieces together, resulting in a welding seam.

At the end of the work, the weld seams must be thoroughly cleaned with a special metal brush in order to obtain a high-quality product.

If you familiarize yourself with all the nuances and strictly follow the sequence of actions, you will be able to weld metal efficiently.

Source: https://moyakovka.ru/process/kak-varit-svarochnym-invertorom.html