What is a moment and a magician

Mig welding: what is it, welding machines and semi-automatic machines

Currently, there is a sufficient variety of welding methods. Based on the tasks to be solved, the materials used and the requirements for the final result, the most suitable technology for connecting parts is selected.

One of them is MIG and MAG welding. In the first case, welding is carried out in helium or argon, and in the second - using nitrogen and carbon dioxide.

Scope of application of the method

Today there is no production where MIG or MAG welding is not used. For example, the manufacture of cars, locomotives, ships, as well as various metal structures.

In addition to being used in various industries, this technology is also widely used in ordinary workshops, service stations, etc.

MIG and MAG welding methods.

So, what is MIG-MAG welding? The basic principle of the Metal Inert/Active Gas method is to carry out work in an inert/active environment. In this case, solder is supplied using a special welding gun to the joint area.

This method has a number of advantages compared to other technologies, namely:

• high degree of protection of products from interaction with the atmosphere;
• ease of use;
• welding quality, which allows you to obtain an even seam without slag and the need for further cleaning;
• method performance.

Types of equipment for MIG-MAG welding

Typically, equipment for performing these types of work is classified into one category. This is due to the fact that they are interchangeable.

MIG/MAG welding technology.

Rectifiers and inverters are used as power sources. They are different from each other and can offer their own pros and cons. In order to correctly select the appropriate version of the device, it is necessary to determine the conditions in which welding will be carried out.

The most suitable option for use in household tasks is an inverter semi-automatic device. It allows for MIG and MAG soldering. This device has a Euro connector, thanks to which replacing or connecting the burner is quite quick and easy.

Using a device of this type will allow you to use it without much effort for installing a gazebo, greenhouse, as well as when performing repair work on the body of a car or other equipment.

The rectifier also allows welding in two modes. You can work both in an inert environment and using flux solder. The device allows for gradual adjustment of the current.

Universal semi-automatic machines, due to the ability to finely adjust welding parameters, will be the best choice in comparison with conventional inverters. If you have to work with the device often, then its high cost will quickly pay off.

MIG/MAG welding technology

The essence of the operation of a semi-automatic welding machine is that an arc burns in an atmosphere of inert gas between the part and the wire - the consumable electrode. It melts the joints of the parts and the solder, forming a weld pool. In this case, the entire process takes place in a protective environment of argon or helium.

Gas consumption for MIG and MAG welding.

As a result of crystallization of the molten metal, a seam is formed. When welding, this technology uses an electrode whose composition is also very close to the products being joined.

The technique allows the use of not only inert, but also active gases. The choice is made based on the materials used. Argon and helium are used to work with non-ferrous metals and their alloys.

Welding of steels is usually carried out in a carbon dioxide environment. In this case, the welding wire is selected with such a composition that it contains a high content of alloying elements. This is due to the fact that carbon dioxide contributes to their waste during operation.

The formation of a seam is caused by the melting of the material of the part and the wire. In this regard, its parameters are determined by the melting and transfer of the electrode metal into the weld pool. The noted processes depend on the selected protective gas, operating modes, etc.

Based on the shape of the wire melt, the following types of welding can be distinguished:

• large-droplet without short circuits;
• without short circuits with small droplet transfer;
• welding with periodic short circuits.

Bottom line

Modern semi-automatic welding machines provide high productivity, seam protection, absence of slag crust, and low sensitivity to oxide formation.

Due to its advantages, MIG/MAG technology has become widespread not only in large production enterprises, but also in everyday life.

Source: https://tutsvarka.ru/vidy/mig

Welding types: MIG MAG TIG MMA

Welding allows you to obtain permanent connections that are exceptionally strong. This indicator at the seam must be no lower than the base material, which is achieved by strict technology requirements and the addition of alloying substances.

In addition, this process is characterized by connection speed, complexity of the acceptable form, and the ability to control and vary basic parameters. MIG/MAG welding is developing most dynamically in industrial applications, but other types are also being improved.

The choice of a specific approach is determined by a number of parameters:

1. Material of the parts to be connected.
2. Production conditions. MIG, MMA and TIG require different organization and production preparation. The set of necessary equipment can vary from a simple power source to a set that includes a feed mechanism with precise adjustment and a compressed gas cylinder.
3. Quality requirements. MIG, MAG, MMA and TIG welding should not always be considered interchangeable - they have different capabilities, including in the formation of the weld.
4. Personnel qualifications. The most accessible in this are MAG and MMA. However, RDS is noticeably more difficult with increased requirements and small dimensions: leg, width, height, etc.
5. Expected performance. The semi-automatic and automatic process turns out to be much faster than the manual one. Depending on this, suitable types are considered and the optimal one is selected.

• 1 MMA
• 2 MIG/MAG
• 3 TIG

MMA

mma technology diagram

In our country, the definition of manual arc welding (and the abbreviation RDS) is common. It is cheaper and easier to organize production and less demanding on equipment.

The connection of two elements in MMA occurs using an electrode - a metal rod coated with a coating containing substances that help maintain the arc, protect the welding zone, and form a seam with the desired properties. When voltage is applied, a stable short circuit is formed between the rod and the workpiece, leading to their mutual melting.

The difficulty may come from requiring welder qualifications. To obtain a neat and reliable joint, skill and long experience are required.

In MMA, special attention is paid to the condition of the electrodes, which should not be wet or crumbling. Do not neglect pre-drying and checking.

Mig/mag technology diagram

The question of what MIG/MAG welding is should not be misleading, despite the unusual designation.

The English abbreviation MIG/MAG (MIG/MAG) hides the well-known semi-automatic welding with electrode wire in a shielding gas environment.

Instead of a rod, a thin wire acts as an electrode, which is semi-automatically fed into the zone where the weld is formed. This compensates for the melting process and simplifies the performer’s task.

Small diameter wire (from 0.8 to 3.0 mm) allows you to obtain compact connection sizes of a few millimeters.

Fundamentally, MIG differs from MAG in the type of protective gas, which is necessary for isolation from the environment with its high oxygen content in the air. Oxidative processes negatively affect the structure through the formation of intercrystalline rust.

MIG welding involves the use of inert gas, which itself does not enter into any chemical reactions, but due to its relatively large weight, tends downward, displacing air. A local microclimate is formed, which shows good results.

MAG welding involves interaction between the natural and created environments, accompanied by the binding of oxygen.

TIG

Tig technology diagram

The decoding of this abbreviation leads to welding with a non-consumable electrode in an environment of inert gases. The main welding material used is thin, sharpened tungsten rods that are strong enough not to melt at operating temperatures. Wire is used as an additive, but its presence is not a prerequisite.

The argon-based protective environment not only sets the correct casting processes, but also creates a melting zone that is local and deep.

TIG is demanding on the level of the welder and on the equipment. Due to its minimal heating, it is usually used to work with aluminum or thin-sheet stainless steel. The same applies to MIG welding.

Flux

Among the types of arc welding, in addition to MIG MMA TIG, it is also worth mentioning that it proceeds under a layer of flux. What flux is has many variations.

All possible materials have in common such qualities as flowability, the ability to influence the formation of a seam at all stages of remelting (including under unfavorable external conditions), and the ability to form a monolithic crust after cooling.

The use of flux shows very good results, but complicates the process itself and implies additional costs. MIG, TIG and MAG are more economical and easier to implement.

Source: https://svarkalegko.com/tehonology/vidy-svarki-mig-mag-tig-mma.html

MIG welding on modern equipment

Now it is impossible to imagine a production that could do without the help of welding. This process, as a way to connect completely different parts from durable material, has found the widest application. Indeed, in most cases, welding is the only effective way to connect metals and structures. With such demand, the progress of this technology cannot wait and develops with the times. Below we will look at the main milestones and directions of modern welding.

Welding MIG, MMA

Manual Metal Arc is literally translated into Russian as “manual arc welding with stick electrodes.” This connection method is a pioneer on the path of welding progress. This process is less technologically advanced than others, which we will discuss below, but to this day remains the most reliable.

The principle of operation is as follows: both the electrode and the workpiece being welded are supplied with direct or alternating current to burn the welding arc. An electrode uses an arc to connect parts of the metal, forming a weld pool of metal and electrode, with molten slag coming out to the surface of the weld.

Progress of welding machines

Modern welding technologies with the index MIG, MAG, TIG are among the most modern methods of arc welding and at this stage of development of the world industry are used literally everywhere. A novice welder does not always know what MIG/MAG welding is.

The definition of this process is as follows: this is the process of joining parts of metals, in which a special protective gas is supplied to the burning zone of an electric arc, pushing atmospheric gases out of the zone of the metals being welded. This is the protective function of gas.

In MIG welding, the weld pool is completely protected from oxygen and nitrogen.

However, a more experienced welder knows what it is – MIG and MAG welding, and how these types differ from each other. The differences lie in the name and their translation. MIG (Metal Inert Gas) translates as “metal, inert gas”.

These inert gases include argon. These gases are relevant for welding aluminum, copper, titanium and all their alloys. MAG (Metal Active Gas) is translated from English as “metal, active gas.” These gases include oxygen, carbon dioxide and hydrogen. This gas is used for weld pools of low-alloy, non-alloy and corrosion-resistant steels.

Operating principle of semi-automatic welding machine

The principle of operation of a semi-automatic device is, first of all, that the wire electrode itself, which during manual arc welding a specialist feeds independently with the help of a hand and a holder, in a semi-automatic device is fed using a motor.

Therefore, this method is called semi-automatic MIG welding. The wire performs a dual function - it is both a conductive electrode and a filler material.

An electric current is applied shortly before the electrode exits the torch, causing an arcing phenomenon to occur between the end of the wire electrode and the metal.

Shielding gas is supplied through a gas nozzle surrounding the wire electrode. Due to its inertness, the burning gas displaces all atmospheric gases, preserving the strength of the structure of the welded seam. However, in addition to the protective function, gas also performs peripheral tasks. The composition of the atmosphere in the electric arc zone depends on the protective gas, which also has a positive effect on its electrical conductivity.

TIG welding

Unlike MIG welding, Tungsten Insert Gas is a manual arc welding performed using a non-consumable electrode in a shielding gas by adding wire. This type is also called argon arc welding. The essence of this process is as follows: shielding gas is supplied to the arc zone through a nozzle, while the non-consumable tungsten electrode is not melted, but is used as a tool for replanting the wire.

According to the classification, TIG, MIG, MMA welding belongs to the manual arc class. This type of welding is recommended for joining extremely small parts with a gap of up to 0.01 mm. The main disadvantage of a TIG connection, compared to MIG welding, is the speed, which is extremely low. If you require excellent quality and are not in a hurry, then this is the ideal choice for an aesthetic welder.

Prospects for welding technologies

In this article, we got acquainted with the main types of welding, which are popular and in demand at the moment in most large industries and in technological chains. Today, MIG welding, TIG technologies, stick electrode welding, etc. are mainly used. However, we have not mentioned the automatic joining methods used in industry.

If we delve deeper into the world of technologies that are under development, we will be able to trace the tendency towards synergetic control schemes, when setting a parameter on automatic systems, for example, the thickness of the metal being welded, sets the corresponding wire feed speed, welding current and other parameters.

This greatly increases work comfort and production efficiency. Among other things, now, in the 21st century, welding is an independent type of production and contributes to the creation of fundamentally new structures.

Welded parts serve at ultra-high and ultra-low temperatures, at pressures, and are capable of operating even in the vacuum of space.

Modern technologies in the field of welding make it possible to work even with plastics, glass, ceramics and other materials. Recently, welding has even been used to connect soft living tissues. Therefore, this profession will develop, improve and remain as in demand as throughout the history of man and progress. And the work of such specialists will and will remain important and necessary.

Source: https://FB.ru/article/326019/mig-svarka-na-sovremennom-oborudovanii

Types of welding. mma, mig, tig, mag – Master Tool

14.11.2018

It is sometimes difficult for a non-specialist to understand the terms and definitions used in welding. The complexity is additionally caused by the fact that there are no strictly regulated and classified methods and techniques. However, manufacturers of welding equipment and materials adhere to generally accepted English abbreviations, which will be discussed in this article.

MMA (RDS)

MMA (Manual Metal Arc) - manual arc welding with piece (coated) electrodes using an inverter or transformer. The technical literature of Soviet times used the designation RDS.

The welding process occurs due to the melting of a metal rod - an electrode coated with a special coating, which have their own classification. Its main purpose is to protect the weld pool from air, preventing oxidation of the metal.

The molten rod forms a weld and the used coating remains as slag.

Covered electrode welding

RDS is possible on both direct and alternating current.

With direct current, there are two options for connecting the ground clamp and the electrode holder, so there is welding with direct and reverse polarity.

Alternating current does not have this feature - how to connect the electrode in this case does not matter. The given reliability rating of welding inverters will help you choose a machine that will last for many years.

Since the MMA method is the most popular due to its simplicity and relatively inexpensive equipment used, you should definitely familiarize yourself with the question of how to learn how to weld with electric welding yourself.

TIG(WIG) or RADS

TIG (Tungsten Inert Gas) - technology of arc welding in an inert gas environment with a non-consumable electrode. Tungsten is a very refractory metal with a melting point of about 3500 C, so it is the basis for the production of this kind of electrodes. Sometimes you can find other variations of this method:

• WIG (Wolfram Inert Gas) - the name is derived from the German spelling;
• GTA (Gas Tungsten Arc) - this abbreviation omits the chemical reaction of the shielding gas.

Because the electrode is non-consumable, the argon welding process occurs according to a different scenario:

• an electric arc is excited between the end of the electrode and the metal being welded;
• filling of the welding seam occurs by supplying a special filler material - a rod - into the welding zone;
• the weld pool is protected by a gas cloud.

TIG welding process

Protective inert gas, i.e. a gas whose molecules do not chemically interact with the base and filler materials during the welding process; in this case, argon is used. That is why the name “manual argon-arc welding” or RADS was assigned to it.

We recommend! Argon welding of stainless steel

Argon can be used when welding consumable electrodes - the MIG method, which will be discussed below.

In the technical characteristics of welding equipment, in addition to the designation TIG, it is always supplemented by a mention of the type of welding current DC (Direct Current) - direct current or AC/DC (Alternating Current / Direct Current) - alternating / direct current. In this case it is very important. For example, welding aluminum with argon is carried out using alternating current.

MIG/MAG

MIG/MAG (Metal Inert/Active Gas) is a method of arc welding in a protective atmosphere of inert/active gas using a consumable electrode in the form of steel or other wire, depending on the type of metal being joined.

Schematic representation of the mig/mag method

MIG or MAG welding usually means semi-automatic welding.

The main objective of this method was the idea of ​​​​creating an “endless electrode”, thereby achieving significant welding productivity.

Indeed, with the RDS method, you often have to change the electrode as it is used up, which in some cases is extremely inconvenient. As with TIG welding, shielding gases are used here.

The inert agent is usually argon and its mixtures, which is suitable, for example, for semi-automatic welding of aluminum and its alloys. The active gas, i.e., interacting with the metal being welded in the process, is usually carbon dioxide (carbon dioxide). You may hear from a welder the phrase “semi-automatic welding in a carbon dioxide environment,” meaning the MAG method.

This method is the most common due to its increased productivity compared to MMA, and gives a better result in the quality of the weld. The rating of household semi-automatic machines based on reviews of experienced welders will help you decide on the choice of a welding machine.

We recommend! Manual arc welding in argon environment

We hope that this article will help you understand the classification of basic welding methods, and will also be useful when choosing equipment and materials with English abbreviations.

Source: https://cs-important.ru/drugoe/tipy-svarki-mma-mig-tig-mag.html

What does TIG, MIG/MAG and MMA welding stand for?

Few readers understand the meaning of the abbreviations mig mag mma used in welding, but a professional welder understands the difference between these methods. Manufacturers of welding equipment and related materials strictly adhere to these designations, so we will talk in detail about each.

Types of welding

With the help of mig mag and mma welding, metal structures and individual parts are firmly connected by melting the edges and forming a single whole. As a result of welding, a strong seam is formed, which has high strength, even under oscillatory loads. You will learn what TIG and MMA are, as well as the decoding of the abbreviations MIG and MAG, in the following sections.

Manual welding option

MMA welding, what is it, the abbreviation literally translates as manual arc welding , which uses an electrode coated or coated with flux. A transformer or inverter is used as a current source. When melted, the rod coating becomes liquid and protects the molten metal from oxidation by air.

After the welding process is completed, the slag covers the seam joint with a durable layer, which is removed by the welder to visually check the quality of the joint. Similar welding is performed when connecting direct or alternating current, with the first option using direct and reverse polarity. MMA is the most common welding in any production.

MIG/MAG

What is MIG welding - a semi-automatic process of joining metals by feeding filler wire, and protection is performed by inert gas . The difference in the abbreviations MIG/MAG is due to the spelling in English or German. The performer guides the torch along the junction of the structure or workpieces, and the thin wire, melting, forms a seam of ideal width.

MIG welding is a process based on the use of an inert gas, which is heavier than air and envelops the weld pool, preventing oxidation of the molten metal. MAG - uses aggressive gases, which include oxygen molecules; welding of metals occurs by combining the created and natural environment.

Advantages of the method

The main advantages of these progressive methods of joining metals:

1. The prostate of welding technology, accessible to novice welders.
2. High quality seam connection and similar productivity, since there is no time spent changing electrodes.
3. Welding is performed in all spatial positions, with low heat input, which is suitable for joining thin sheet metal.
4. There is no need to carry out subsequent processing of the seam.
5. Long seams are performed without stopping and re-activating the arc, which greatly simplifies the entire process.

It is because of these advantages that MIG/MAG is used in automatic automobile assembly lines where robots are used for welding work.

Rectifier or inverter?

Experienced welders choose an inverter for everyday work , because additional modes and built-in functions simplify the technology, this is especially true when connecting parts and structures made of aluminum, stainless steel and complex refractory alloys. The weight of the device and the ability to connect to any electrical network also matter.

The transformer is characterized by exceptional operational reliability and low cost, but consumes much more electricity . Its mass is significant, so it is not very mobile, and it is used for the simplest types of welding.

Equipment

You already know what MMA TIG MIG is, now let’s talk about the types of machines for each type of welding work.

With inert gas

The gas is in cylinders with specific markings; a reducer is installed on top that regulates the amount of gas supplied. The MIG method uses inert gases , which are much more expensive than active analogues, for example, the price of carbon dioxide is 45 times less than argon, and compared to helium, the cost is reduced by another 3.5 times.

When welding MAG, carbon dioxide or nitrogen is used as protection, but to avoid a negative impact on the result, wire with the addition of manganese or silicon is used, since they do not allow the molten metal to oxidize.

With non-melting rod

In the CIS countries, the TIG method is argon arc welding, named after the gas used for protection; a non-consumable electrode simplifies the entire process, and the absence of foreign inclusions allows you to obtain a high-quality seam.

The pulsed version of the welding process is similar in its properties to TIG, only a non-constant current is used, this mode is found in MAG/TIG units. It is used for joining thin sheets, because...

there is no overheating or warping of the surface, and the seam joint has the appearance of scales.

The MMA welding process was described in detail earlier, recall that it is characterized by the formation of an arc between a consumable electrode and the workpiece.

Semi-automatic

Almost all service stations have a MIG/MAG welding machine installed, because its use produces a high-quality seam that does not require additional processing. Inverters are used because they are connected to a regular electrical network, have small dimensions and weight, and are also mobile.

Source: https://svarka.guru/vidy/thermo/dugovaya/tig-mig-mag-mma.html

MIG welding: specifics of the method, how it works, where it is used, pros and cons, equipment

You have the opportunity to read about welding about the types and types that you may learn about for the first time. But the electric arc is what unites them.

And without this arc it is impossible to form seams. With the use of gas, MIG/MAG ranks first in popularity.

This line of work is easy to use, well suited for welders with no experience, and used successfully by experienced welders.

Thanks to the instant, it is possible to easily weld various types of metals with different thicknesses and with any complexity of the seam. This article will tell you about MIG, or more precisely about the peculiarities of welding. Or rather, in a protective gas environment.

MIG and MAG are

This is a semi-automatic technique. Please note that this version, since its melting is in a gas protective environment. There is also an automatic and manual version.

Otherwise, on the Internet you can find such types of welding as:

• electric arc (in gas);
• arc (gas protective environment);
• moment;
• magician;
• GMAW (“Gas metal Arc welding”).

The following picture shows TIG and MIG/MAG – schematically. You have the opportunity to compare and consider them in detail. With continuous current there is an option with MIG/MAG.

There are two types of polarity: forward and reverse. The article immediately used the abbreviation MAG, the difference from MIG is that MAG is using gas (carbon dioxide), semi-automatic.

Mag differs from mig in that argon can be replaced with carbon dioxide (cheaper when purchased). Also, this option can only connect zones made of alloyed and low-alloyed materials, and this is limiting.

Prefer professional semi-automatic machines with the ability to function in MIG/MAG. You will have more possibilities by also using wire of different diameters. Once you understand MIG, you can choose the best equipment for this method.

Device and additional equipment

Semi-automatic (standard) is ideal. Gas (don’t forget about the pressure reducer), semi-automatic, cable, transformer (producing current), gas burner, various hoses, equipped with additional wire (filler) output and mechanism. This is considered a set of welding equipment.

MIG is work in gas protection with a melting electrode. But here the electrode was replaced, and filler wire (aluminum) was used. Recommendation: the wire should be selected taking into account what exactly will be welded.

The wire is wound onto the drum set and mechanically transferred to a specific place of work. What does the speed feed depend on? The answer is simple: from the diameter and current parameters (you set it yourself).

All you have to do is press the button to point the burner in the desired direction.

As soon as the arc is lit, the wire will begin to be transmitted at the stitching site. At the same time, the gas will flow around the weld pool, protecting the metal from oxidation and the creation of defects.

And gas is a coated electrode (also in standard MMA), if we compare it with other types of welding. Although here the gas is supplied from outside, but with MMA it will form when the electrode melts.

Plus eclipsing minus

It's not uncommon for customers to complain about MIG. The device cannot be conveniently hung on the shoulder, and you also need to carry a large gas cylinder and other things. Without a special cart, it is impossible to easily move from place to place when necessary.

But the advantages of welding easily correct these disadvantages. Since no unsafe fumes are emitted when working with the device, the arc is not difficult to ignite (this is a big plus for beginners), wire is saved, and you can weld almost all metals of different thicknesses.

Working method

The welding voltage should not exceed 30V. The best value to use is 18-30V, it is adjusted specifically for the purchased device.

Make sure that the semi-automatic machine does not have the ability to automatically adjust the wire feed speed. This was specifically designed to stabilize the arc.

Although for welders with experience in their field, this inability to adjust the wire feed themselves causes inconvenience.

But in fact, this is convenient, because the feeder is complex and technologically advanced, and helps the welder avoid unnecessary movements and makes it possible not to interrupt his work.

For example, in a semi-automatic MIG/MAG machine, the wire feeder independently determines the need for deceleration and acceleration to ensure stable arc use.

This clever device helps keep the wires from melting into the torch, which will help prevent them from sticking in the torch or to the alignment when first fed. And thanks to this mechanism, pulse stitching is easily performed.

MIG/MAG is often performed when using reverse polarity, as well as constant current. More optimal settings.

If you have some experience and intend to start experiments, set the polarity to straight and the current to non-constant.

A machine with advanced settings may have different modes. Let's analyze them in more detail below:

• "Short arc" mode. Thin metal. Current - less than 200 amperes.
• "Spary arc" mode. Wire with a diameter of more than 1 mm. Universal mode.
• "Pulse arc" mode. Large diameter wire. Steel and aluminum.
• "Pulse on pulse arc" mode. Aesthetic seam.

Final word

I hope this article will help you.

Use our practice tips and tell us about your experience.

Let safety and protection be a priority. Good luck with your work!

Source: https://prosvarku.info/tehnika-svarki/mig-svarka

What is MMA, TIG, MIG/MAG - description of technologies

It is sometimes difficult for a non-specialist to understand the terms and definitions used in welding. The complexity is additionally caused by the fact that there are no strictly regulated and classified methods and techniques. However, manufacturers of welding equipment and materials adhere to generally accepted English abbreviations, which will be discussed in this article.

MIG/MAG welding technology

The semi-automatic welding system consists of a DC power source, wire feeder, reel, torch and gas cylinder.
Current is supplied to the arc through the welding wire (the wire is connected to the positive pole), which, when melted, is transferred to the metal being welded. Continuous wire feeding is necessary because wire material is constantly consumed during the welding process.

MIG/MAG - Metal Inert / Active Gas - arc welding with a consumable metal electrode (wire) in an inert / active gas environment with automatic feed of filler wire. This is semi-automatic gas shielded welding - the most versatile and common welding method in the industry. This welding method is sometimes referred to as GMA (Gas Metal Arc) .

The use of the term “semi-automatic” is not entirely correct, since we are talking about automation of only the supply of filler wire, and the MIG/MAG method itself is successfully used in automated and robotic welding.

The phrase “in carbon dioxide,” to which many specialists are accustomed, is deliberately omitted, since this method increasingly uses multicomponent gas mixtures, which, in addition to carbon dioxide, may include argon, oxygen, helium, nitrogen and other gases.

Depending on the metal being welded and its thickness, inert, active gases or mixtures thereof are used as shielding gases. Due to physical features, the stability of the arc and its technological properties are higher when using direct current of reverse polarity.

When using direct current of direct polarity, the amount of melted electrode metal increases by 25-30%, but the stability of the arc sharply decreases and metal losses due to spatter increase.

The use of alternating current is impossible due to unstable arc combustion.

When welding with a consumable electrode, a seam is formed due to the penetration of the base metal and the melting of additional metal - the electrode wire.

Therefore, the shape and dimensions of the weld, among other things (welding speed, spatial position of the electrode and the product, etc.), also depend on the nature of the melting and transfer of the electrode metal into the weld pool.

The nature of the electrode metal transfer is determined mainly by the electrode material, the composition of the shielding gas, the welding current density and a number of other factors.

With the traditional welding method, three main forms of electrode melting and transfer of electrode metal into the weld pool can be distinguished.

The welding process with periodic short circuits is typical for welding with electrode wires with a diameter of 0.5-1.6 mm with a short arc with a voltage of 15-22 V. After the next short circuit (1 and 2 in Fig.

below, a) the force of surface tension pulls the molten metal at the end of the electrode into a drop. As a result, the arc length and voltage become maximum.

At all stages of the process, the feed rate of the electrode wire is constant, and the speed of its melting varies and in periods 3 and 4 is less than the feed rate.

Rice. The main forms of melting and transfer of electrode metal: a) short circuits; b) drip; c) jet

Therefore, the end of the electrode with a drop approaches the weld pool (the length of the arc and its voltage decrease) until a short circuit occurs (5). During a short circuit, the welding current sharply increases and, as a result, the compressive effect of electromagnetic forces increases, the combined action of which breaks the liquid metal bridge between the electrode and the product. During a short circuit, a drop of molten electrode metal passes into the weld pool. Then the process is repeated.

The frequency of periodic closures of the arc gap can vary within 90,450 per second. For each electrode wire diameter depending on the material, shielding gas, etc. There is a range of welding currents in which short-circuit welding is possible. With optimal process parameters, welding is possible in various spatial positions, and losses of electrode metal due to spattering do not exceed 7%.

An increase in the welding current density and arc length (voltage) leads to a change in the nature of melting and transfer of the electrode metal, a transition from short arc welding with short circuits to a process with rare short circuits or without them. Electrode metal is transferred into the weld pool irregularly, in separate large drops of various sizes (Fig. above, b), clearly visible to the naked eye.

Rice. Changes in current and arc voltage during pulsed-arc welding: In, Un-current and voltage of the main arc; Ii, Ui - current and voltage during the pulse; tn, ti—pause and pulse duration

At the same time, the technological properties of the arc deteriorate, welding in the ceiling position becomes more difficult, and losses of electrode metal due to waste and spattering increase to 15%.

To improve the technological properties of the arc, periodic changes in its instantaneous power are used - pulsed-arc welding (Fig. below). The heat generated by the main arc is not sufficient to melt the electrode wire at a rate equal to its feed rate.

As a result, the length of the arc gap decreases. Under the influence of a current pulse, the electrode accelerates melting, ensuring the formation of a drop at its end. A sharp increase in electrodynamic forces narrows the neck of the drop and throws it towards the weld pool in any spatial position.

You can use single pulses or a group of pulses with the same or different parameters. In the latter case, the first or first pulses accelerate the melting of the electrode, and subsequent ones drop a drop of electrode metal into the weld pool.

The stability of the process depends on the relationship between the main parameters (the magnitude and duration of pulses and pauses).

By appropriately selecting the main arc current and pulse, you can increase the melting rate of the electrode wire, change the shape and size of the weld, and also reduce the lower limit of the welding current, which ensures stable arc burning.

At sufficiently high densities of constant (without pulses or with pulses) welding current of reverse polarity and when the arc burns in inert gases, very fine-droplet transfer of electrode metal can be observed.

It received the name “jet” because when observed with the naked eye, it seems that molten metal flows into the weld pool from the end of the electrode in a continuous stream (see figure above, c).

A change in the nature of the transfer of electrode metal from droplet to jet occurs when the welding current increases to “critical” for a given electrode diameter.

The value of the critical current decreases when the electrode is activated (certain easily ionizing substances are applied to its surface in one way or another) and the electrode extension increases.

Changing the composition of the shielding gas also affects the value of the critical current. For example, adding up to 5% oxygen to argon reduces the critical current value.

When welding in carbon dioxide, it is impossible to obtain jet transfer of electrode metal without the use of special measures. It is not obtained when using a current of direct polarity.

When switching to jet transfer, the flow of gases and metal from the electrode towards the weld pool sharply intensifies due to the compressive action of electromagnetic forces. As a result, the layer of liquid metal under the arc decreases, and a local depression appears in the weld pool.

Heat transfer to the base metal increases, and the seam takes on a specific shape with an increased penetration depth along its axis. With jet transfer, the arc is very stable - no fluctuations in welding current or voltage are observed. Welding is possible in all spatial positions.

Welding parameters.

Since the appearance of the welding arc and weld pool is determined by the welding parameters, the welder does not need to constantly refer to tables and diagrams of the relationships between various welding parameters.

• The welding voltage determines the appearance of the weld pool, but its dimensions (at a constant voltage) can be adjusted manually by changing the movement of the torch.
• The wire feed speed is proportional to the welding current.

For Short Arc/Spray MIG welding and Pulsed MIG welding, simple and fast synergistic settings are available depending on the welding sources used.

In synergetic mode, welding parameters are set automatically based on operating conditions (material, thickness, gas, wire, speed), and through microprocessor control are dynamically controlled and maintained in balance throughout the entire welding process.

This allows for exceptional welding results in terms of weld quantity, quality and appearance for all conditions and applications.

Gases

The very name of the semi-automatic welding method MIG-MAG indicates the use of a certain gas in the welding process: inert (Ar) for MIG welding (Metal Inert Gas) and active (CO2) for MAG welding (Metal Active Gas).

Carbon dioxide (CO2)ArgonHeliumArgon-helium mixtureMixture of Argon-CO2 and Argon-CO2-Oxygen

The use of CO2 as a shielding gas provides good metal penetration, the ability to feed wire at high speeds and obtain seams with good mechanical characteristics at relatively low costs. On the other hand, when using this gas, problems with the final chemical composition of the compound are possible, since the weld pool turns out to be oversaturated with carbon with a lack of easily oxidized elements. Welding using pure carbon dioxide creates another set of problems, such as weld spatter and joint porosity due to the inclusion of carbon monoxide bubbles.

Pure argon is used only when welding light alloys. For welding stainless steels containing chromium and nickel, it is better to use a mixture with the addition of oxygen and carbon dioxide in an amount of 2%, as this improves arc stability and weld shape.

This gas is used as an alternative to argon and allows for greater penetration depth (for thick parts) and higher wire feed speed.

Allows you to obtain a more stable arc than when using pure helium and greater penetration depth and wire feed speed than when using pure argon.

These mixtures are used in SHORT ARC welding of ferrous metals as it increases heat transfer. These mixtures can also be used for welding using the JET TRANSFER method. Typically the mixture contains 8% to 20% carbon dioxide and approximately 5% oxygen.

Source: https://www.rudetrans.ru/o-svarke/tekhnologiya-svarki-mig-mag/

Difference between MIG and MAG welding

Welding using the MIG or MAG method is one of the most popular welding technologies, which is semi-automatic welding in a protective gas environment using a metal electrode, which simultaneously acts as a filler wire. This procedure is quite popular in the industrial industry.

The MIG and MAG welding techniques are actively used in automated, robotic welding. In Europe, this type of welding work is abbreviated Gas-Metal-Arc, abbreviated as GMA. The technology is also very popular in America and Japan. The main advantage of this method of welding joints of parts is the simplicity and automation of the process, accompanied by high productivity.

The essence of the welding procedure

Welding equipment for this technology includes:

• feeder;
• A rectifier characterized by a smoothly falling, rigid current-voltage property that serves as a power source. Therefore, in the event of oscillatory movements of the welder’s hand, the arc length will be adjusted automatically;
• For work, gas cylinders or a centralized supply of the gas mixture can be used.

Flux-cored wire of solid cross-section can be used as an electrode consumable wire when welding using the MIG and MAG methods. This tool is fed automatically at a constant speed. The torch is moved manually by the welder. The weld pool and electric arc are protected from the external environment using a gas flow: active gas - MAG, inert gas - MIG, which is supplied by a torch through a nozzle.

Principle of operation

The principle of operation of mig welding is as follows: in the process of joining metal samples, the electrode moves along the joining line. The wire is fed automatically through the torch, then it is melted under the influence of the welding arc.

The technology is considered semi-automatic due to the fact that the welder has to move the torch manually.

• It is better to use direct current with reverse polarity to operate the arc. Of course, you can use alternating current with straight polarity, but in this case the arc will not be stable, as a result of which the molten material will vigorously splash.
• It is quite important to correctly set the operating mode on the welding equipment: type of electric current, welding current, diameter of the welding wire used, electrode feed speed, arc voltage, and welding speed.
• The speed and supply of shielding gas also need to be constantly monitored.

Thanks to this technology, it is possible to connect elements made of stainless, high-alloy, and low-alloy steels. Aluminum, copper, and aluminum alloys are perfectly weldable.

Depending on the welding arc, MIG welding can be stationary or pulsed. There are situations when it is necessary to increase the power of the arc, for which pulse technology is provided: the melting speed of the electrode does not correspond to the speed of its feeding, therefore, to melt it as quickly as possible, a current pulse is used - a drop is formed at the end of the wire.

Welding metals using the pulse method has advantages over the stationary method: minimal spattering of metal, low current level, transition, due to a short circuit, to jet transfer.

How is soldering done?

When performing soldering, gas is supplied through a specialized nozzle attached to the welding unit. In production, work using MAG technology is usually carried out in specially treated rooms.

When using this technique, the main thing is a uniform, non-stop wire feed, then a neat and durable weld is guaranteed.

Therefore, such work should be carried out exclusively by experienced welders, especially when assembling high-precision structures.

Another difference between MIG soldering and MAG is that in the first case the wire is fed automatically, manually.

Advantages of MIG soldering

• Simplicity of technology that can be easily learned.
• High performance;
• There is no need for additional processing of welded joints.
• High quality results.

Another advantage of this technique is the ability to perform a long weld without stopping and re-igniting the welding arc. This greatly simplifies the entire welding procedure.

Source: https://electrod.biz/vidy/razlichie-mezhdu-svarkoy-mig-i-mag.html

Semi-automatic MIG/MAG welding

MIG/MAG – welding of materials using metal electrodes. This abbreviation means that welding is carried out in electrodes located in inert (MIG) and active (MAG) gas. Unlike MMA and TIG technologies, MIG/MAG welding has high productivity, ease of use and an increased degree of mechanization.

Seam formation

In MIG/MAG welding, a weld is formed by melting the electrode wire. As a result of this process, the basic welding materials crystallize. The resulting seam is reliably protected from exposure to atmospheric air by a gas film. Its size and shape depend on the characteristics of the transfer of material into the weld pool. As heat transfer increases, a small depression is formed in the weld pool, which affects the weld formation procedure.

Advantages and disadvantages

The following advantages of welding in semi-automatic mode are highlighted:

1. Allows the use of high voltage welding current.
2. High quality welds.
3. Allows you to weld products with a wide range of thicknesses.
4. Allows the process of seam formation.
5. Does not require the use of slag or flux.
6. Allows you to create tight connections of galvanized products without damaging the coating of the parts being welded.
7. Provides the ability to weld thin steel or aluminum sheets up to 0.5 mm thick.
8. Base materials are not exposed to dirt or corrosion during welding.

The main disadvantages of MIG/MAG technology are:

1. Requires the purchase of expensive semi-automatic devices.
2. High complexity of technology.
3. It is impossible to weld parts in hard-to-reach places, which is due to the large difference in the sizes of the torch and electric holder.
4. Mandatory preparation and cleaning of the edges of the parts to be welded.
5. The ignited arc emits a large amount of light energy, which leads to an increase in radiation. For this reason, the welder is required to use protective face masks while working.
6. Strong splashing of metal in a molten state.

Compared to TIG technology, MIG/MAG welding is used in industrial sectors. This is due to the complete mechanization of the welding process, which reduces production costs in the long term.

Application area

MIG/MAG technology is used for:

1. Welding plates with a thickness of no more than 0.5 mm. When working with these materials, it is necessary to increase the heat supply intensity. This will avoid plate deformation and increase productivity.
2. Welding low-alloy materials with low carbon content.
3. Welding products made of iron or aluminum alloys in all spatial positions
4. Welding plates made of non-ferrous metals of medium size (up to 0.2 cm).

Due to the fact that the MIG/MAG method allows welding dissimilar metals of all classes, it is actively used in many industries. This technology has found application in the production of automobiles, marine vessels and offshore structures. The use of semi-automatic welding in production requires a lot of professional skills and abilities from the welder.

The worker must be able to operate welding machines consisting of a large number of substructures. When organizing industrial production using MIG/MAG welding, you need to carefully prepare the work shops: set up ventilation and purchase stationary welding devices.

Otherwise, the gas system will operate unstably due to exposure to drafts.

Types of equipment for MIG/MAG welding

To weld parts using MIG/MAG technology, power sources are required. Their role is played by rectifiers and inverters. They allow you to increase the amplitude of high-frequency voltage. There are 3 categories of inverters for welding:

1. Household: most often used by novice welders for one-time projects. They can weld small parts. The welding current of household rectifiers is no more than 200 A.
2. Professional: Used by welders working in small commercial settings. They can weld large parts without losing quality. The welding current of professional inverters is 300 A.
3. Industrial: used in large industrial organizations. They are capable of continuously welding large structures while maintaining basic weld size and shape requirements. The welding current of industrial rectifiers is no more than 500 A.

Inverters ensure stability of the welding current and reduce the range of spatter of the molten electrode. The versatility of this device allows it to work with stainless steel and aluminum. Rectifiers consume a small amount of electricity. They are small in size, which improves comfort during welding work.

In domestic conditions, an inverter semiautomatic device with a Euro connector is most often used, allowing you to quickly connect the burner. Rectifiers allow welding in 2 modes, both in an inert gas atmosphere and using fleece. For frequent use, it is recommended to buy universal welding machines that can work using different welding technologies. Their main disadvantage is their high cost.

Selecting a device

When purchasing a welding machine, you must consider the following indicators:

1. Power type: It is recommended to purchase devices that operate on direct current. When activated in reverse polarity, these devices provide better performance. Devices operating with alternating current and straight polarity are not able to maintain a stable voltage on the arc, which leads to increased metal spattering and a change in the shape of the weld.
2. Mains voltage: single-phase or three-phase. Universal welding machines operate at a voltage of 220 V. It is important that the devices are protected from power surges. Otherwise, they will not be able to work in networks with different power supplies.
3. Temperature limits: Most welding machines operate at temperatures between -40°C and +40°C. At higher values ​​of this indicator, devices are automatically turned off.
4. Availability of additional options: modern machines are capable of performing MMA and TIG welding. By combining many functions, they can be used to solve a large number of problems. Also, modern models have support for HotStart, AntiStick and ArcForce options.

The main technical characteristics of the welding machine are indicated in the device passport. It is important that the device is made of durable materials and has a long warranty period.

The main consumable material required for welding is welding wire. Its diameter must correspond to the thickness of the material being welded. Also, the part and the wire must be made of identical materials.

When welding, it is necessary to select the correct shielding gas. When processing parts made of non-ferrous metals, it is better to use inert gaseous substances (helium, argon and their mixtures).

When working with iron alloys, it is recommended to use carbon monoxide. It is important that in this case the welding wire contains an increased amount of silicon and manganese.

Experienced specialists recommend using mixtures of active and inert gases that reduce the range of metal splashing.

Source: https://stankiexpert.ru/spravochnik/svarka/svarka-mig-mag.html

What is flash welding and what equipment is needed for it?

Connecting metals by welding can be carried out using several technologies, which have a single principle, which is the formation of an electric arc. Let’s immediately make a reservation that there are also arcless types of welding. The MIG (metal inert gas) mode has gained its popularity not only due to its functionality and wide range of applications. The principle of the technology is that welding is the melting of metals in a protective gas environment.

This type of welding, with the necessary equipment, is available even to beginners who decide to improve their skills.

This method has another variety (MAG), which differs only in the gas used as protection.

Thanks to the development of the mig welding method, it has become possible to work with such “capricious” metals as aluminum, titanium, and nickel. Modern inverters operating in MIG/MAG mode provide convenient conditions for the welder, allowing control of parameters such as current strength, amount of gas, and amount of additive supplied. This is why they received the name “semi-automatic”, and welding itself is often called semi-automatic.

Today, the master chooses the operating mode based on the initial conditions (type of metal, thickness of parts, availability). A modern semi-automatic inverter is capable of operating in one of the selected modes. Additional materials include wire, which acts as an additive, and gas. Argon is used for MIG welding, and a mixture of nitrogen and carbon dioxide is used for MAG welding.

Equipment

To understand the principle of controlling a MIG welding inverter, you need to know that this welding mode is a special method of melting metals with the addition of an additive, but this all happens in a gaseous environment.

The necessary equipment must ensure the supply of voltage to the electrodes, the regulation of this voltage, and the supply of wire and gas to the contact zone.

An inverter semi-automatic machine, due to the presence of a wire feed mechanism, cannot be called compact, however, modern technologies have made it possible to significantly reduce the weight and dimensions of the device without sacrificing its technical characteristics.

The burner cable is connected to the Euro connector located on the front panel of the inverter, and the gas hose coming from the cylinder is connected to a special fitting at the back. The wire in the form of a reel is placed in the compartment intended for it. Large semi-automatic machines are assembled on a platform with wheels. A gas cylinder is also placed on it. Such a platform is convenient to transport around the facility.

The control elements of the inverter include a current regulator. The most expensive models are equipped with additional functions. To get an arc, you need to bring the holder to the welding site and press the key. The rest of the process is automated.

Technology

The principle of MIG welding is that the edges of the joining metals and solder are heated, they partially melt, forming a weld. But under normal conditions, the released gases would lead to the formation of cracks and pores at the junction. In addition, metal spattering would be observed. The inert gas does not react with the liquid metal and at the same time it displaces hydrogen, and the surrounding air, in particular oxygen, cannot enter the weld formation zone.

The role of solder is played by the wire, which is also a consumable electrode. The wire material may vary. It should be as similar as possible to the workpiece material in its chemical and physical properties. The area where molten metals are localized is called a weld pool. It is this area that is protected by argon. After the metal crystallizes in the bath, a seam is formed. The purpose of the active gas when operating in MAG mode is the same as that of the inert gas.

After the arc is formed, the melting wire begins to flow along the guides to the end of the torch. The wire feed speed is adjusted automatically. Some devices provide functions that significantly facilitate the welding process and stabilize the arc. Gas is supplied to the burner under pressure. It blows air over the weld area, preventing the appearance of oxide on the molten metal.

The role of inert gas can be understood if we compare this type of welding with MMA arc welding. Only there does the coating of the electrode provide a protective environment during combustion. When connecting electrodes, polarity must be observed, as it can be direct or reverse. The choice of polarity depends on the specific conditions. In most cases, mig welding is carried out with direct current, but sinusoidal current is also used.

The open circuit voltage is 30-40 V. The current strength is adjusted depending on the diameter of the wire, but the thickness of the metal sheet is decisive. On some inverters, the wire feed is not adjustable, but this is not considered a negative quality, since such models have an automatic arc correction function. The correspondence of the current strength to the diameter of the electrode for different metals is different, so it is recommended to take exact values ​​from specialized sources.

Typically, the wire feed mechanism is quite complex in design. The supply system can have several purposes at once.

• It feeds the wire first at a lower speed and then at a higher speed. At a low feed speed, it is possible to ignite and obtain a stable arc.
• To prevent the wire from sticking when the welding is stopped, the current stops slightly earlier than the wire stops.
• At the beginning of the arc ignition, an additional current pulse is supplied, eliminating the possibility of sticking.
• The system allows you to work in pulse mode.

In addition, the device itself can change operating modes. The Short Arc mode is relevant when the welding current does not exceed 200 A. Here we are talking about welding thin sheet metal. In Spray Arc mode, the current exceeds the specified value and the wire diameter is 1 mm or more. For non-ferrous metals, use the Pulse Arc mode.

Wire

Many experts claim that MIG welding is gas shielded arc welding with a consumable electrode. In principle, this is so, only the wire acts as an electrode, which increases productivity. Let us remind you that when working in manual arc welding mode, you have to constantly change the used piece electrodes. The wire plays one of the key roles, so it must be selected based on the initial conditions. Traditionally, there are four types of wire:

1. steel;
2. aluminum;
3. copper-plated;
4. powder

Copper-plated and powder are considered the most popular, as they are more versatile and, moreover, easy to use.

• Firstly, such additives are available in any specialized store.
• Secondly, at high speed there is virtually no splashing.

Not only professionals, but also novice amateurs can work with flux-cored wire. Components in powder form, represented by various chemical compounds, ferroalloys and ores, greatly facilitate the welding procedure. The only inconvenience is that the integrity of such a wire, made in the form of a tube, cannot be damaged.

Steel and aluminum wire is used for the MAG mode, that is, in a carbon dioxide environment. If you do not have enough experience with mig welding, then each time you will have to clarify which material to use for a particular metal.