How to weld cast iron using electric welding

Welding cast iron at home using an electrode

                                 Methods of working with cast iron have their own characteristics. They have a number of properties that are different from steel. Welding cast iron with an electrode can cause some difficulties for a novice or self-taught master. Learn how to cook cast iron using electric welding in this article.

Features of the material

Cast iron is a mixture of iron and carbon. There are several types of cast iron with impurities:

• Gray (1.9% - 2.5% silicon, 3.2% - 3.5% carbon, manganese, phosphorus and sulfur are also present) - plastic and viscous, processed by cutting, used in artistic casting;
• white (2.14% - 6.67% carbon) - brittle but hard, later melted down into steel;
• malleable (2.4% -3.0% carbon) – obtained from white cast iron by heating;
• high-strength (3.2% - 3.8% carbon) - obtained using the addition of magnesium, the properties of this material are close to the properties of carbon steels.

The difficulty of processing cast iron is as follows:

• microcracks and pores form on the surface, which affects the strength of the alloy;
• reddened formations appear;
• metal cutting tools quickly become dull;
• a thin layer of material crumbles under the influence of high temperature.

Gray cast iron is used for welding.

Preparation for welding

The first step is to clean the metal. This is done with a grinder. An attachment called a petal wheel is used. Other attachments can also be used. Then the surface is degreased with a solvent, such as acetone.

If a crack is processed, it is cleaned until it ends, holes with a radius of 5 mm are made.

Preparation for work has the following features:

1. the use of studs (consisting of steel, the diameter is 40% or less of the thickness of cast iron);
2. cutting edges (give a spherical shape);
3. use of special electrodes.

In addition to the features and nuances, we will tell you how to cook cast iron correctly.

Welding technology

Experts distinguish 3 electric welding technologies:

• cold;
• semi-hot;
• hot.

When surfacing a weld, the master must take into account the following points.

• Do not quickly cool the surface of the part. When the master performs joining together with steel, the cooling interval of the latter is extended. To do this, sprinkle the surface of the part with coal or dry sand. A rapid decrease in temperature is fraught with the appearance of cracks.
• The liquid state of cast iron is characterized by fluidity. This should be taken into account during operation.
• When TIG welding, it is necessary to ensure a tight weld. Electric welding of two heterogeneous metals is considered difficult. When carrying out actions, it is worth considering the properties of all materials involved.

Professional welders strictly follow the technology of welding cast iron with electrodes. They are familiar with all the documents that describe the process and algorithm for working with cast iron and other metals. They are not faced with the question of how to brew cast iron.

Electrodes are used for the inverter (current source). You can purchase them or create them yourself.

The characteristic properties of reconstruction of cast iron parts by electric welding consist of the following points:

• Surface preparation - removing imperfections. This is done manually or mechanically. If the damage is located at a distance of more than 20 mm from each other, they are removed separately. If they are closer, they should be removed together.
• It is important to correctly determine the composition of the metal; the range of all work depends on this. An experienced welder determines how resistant a material is to heat. Gray cast iron is easier to process; additional measures are taken when the metal darkens. Black is the least amenable to electric welding. If the material is oiled, then the question “how to weld cast iron” disappears. This becomes impossible. Malleable cast iron heats up before performing operations on it; other options will not lead to the desired result.
• To maintain high-quality seam adhesion, in some cases steel pins are used: the required number of them is inserted into the surface to be treated. They help strengthen the weld and reduce the proportion of carbon in the weld material. The volume of graphite in the electrode should be controlled independently.
• When carrying out welding manipulations, it is necessary that a little molten material is in the weld pool. When performing the task, it is mixed evenly.
• Cast iron filler rods may be useful for welding.
• When finished, the part is covered with a layer of sand or crushed coal to prevent rapid cooling. Quality is checked visually. There should be no uncooked areas left on the seam. If inaccuracies, burns and cracks are detected, the surface is cleaned and the steps are repeated. When joining cast iron with other metals, a double seam is applied.

The part may be used after cooling.

Electrodes for welding

When performing operations on alloys, questions arise: is it possible to cook them, how to combine different metals. Experienced craftsmen know how to cook cast iron so that the part will last a long time.

During the electric welding process, carbon in the alloy is burned with a conventional electrode, so graphite is often additionally added to the electrode. Materials that contain nickel and copper are widespread. The use of such materials is justified by their properties.

• Nickel dissolves in iron. The resulting seam is not hardened and becomes pliable for subsequent processing.
• Copper does not dissolve in iron, but forms a very strong weld. Craftsmen specifically choose this type to achieve high strength.

The modern market offers a dozen different electrodes that have unique properties. They are used in appropriate situations.

Common brands of electrodes:

The latter type helps to get a good seam. It is used for cold and hot welding.

The first option has proven itself when used during cold welding, as well as for joining cast iron and steel with a seam.

The electrode may contain substances such as:

• ferrosilicon;
• termite;
• marble;
• aluminum;
• liquid glass;
• titanium powder.

Instead of an electrode, filler wire is sometimes used. It has a graphite rod.

Welding methods

There are 3 options.

1. The hot method is considered the main and correct method. Its essence is as follows: before starting the electric welding process, the workpiece is heated to a certain temperature. It varies from 600 to 650 degrees. It is problematic to use the method outside of enterprises, since you need a special heating device, knowledge of the nuances, and the ability to interact with heated metal.
2. The semi-hot method is similar to the first method, the temperature is half as much - 300-350 degrees.
3. The cold method does not involve heating the workpiece. It has features that are worth considering. The method is used for welding cast iron with an electrode at home.

The electric welding process uses a current source called an inverter.

cutting

There are 2 types of cutting cast iron - thermal or mechanical. Let's consider several ways:

• cutting with a grinder is a simple method;
• if necessary, cut pipes using pipe cutters;
• reciprocating saw;
• cutting with an electrode;
• oxy-fuel cutting;
• plasma cutting.

There are many options; at home, an angle grinder is most often used.

Security measures

It is important to take care of your health when interacting with metals and electrical devices. Let's list the important points:

• work must be carried out in a room that is lit and ventilated;
• the electric welding machine must be grounded;
• the material cannot be cooled sharply, so it must be protected from moisture;
• use personal protective equipment: gloves, goggles and special clothing.

For improved perception of information, it is worth watching the video.

Source: https://svarkaed.ru/svarka/svarka-metallov/svarka-chuguna-v-domashnih-usloviyah-s-ispolzovaniem-elektroda.html

Welding cast iron with an electrode at home

In the event of a leak in a car manifold or a crack in a cast iron pipe, turn to a welder for help. But unlike low-carbon steels, cast iron welds much worse. Frequent defects are pores on the surface of the seam, and after welding work you can hear the cracking of the product, which indicates the formation of microcracks in the heat-affected zone.

In industrial conditions, this metal, with a high carbon content, is combined with the preliminary preparation of the product, heating the material with induction currents and ensuring its smooth cooling. But how to solve the problem in everyday life? Welding cast iron with an electrode at home is carried out with a conventional inverter.

It is possible to obtain a high-quality connection by properly preparing the surface of the product and choosing the right welding modes.

How to cook cast iron at home

At home, cast iron can be welded using an inverter or transformer, the operation of which is supplemented by a converter that supplies direct current to the holder. This promotes high-quality penetration of the base metal and reduces spatter when the arc burns.

The welding process, performed in a garage or yard, can be carried out in two ways. If you need to weld a crack in a manifold or eliminate a hole in a product, you can use the cold method. This means carrying out welding work without preheating the metal.

The defective area is cleaned of oxides and dirt. If the crack is narrow (less than 1 mm wide), then it is necessary to file it with a thin grinder disc. This will allow the molten metal to flow deeper and strengthen the structure of the seam.

The cold method is used on non-critical connections that, after restoration, will not experience serious stress.

In the case of repair work on cast iron gears, where a tooth has broken off and its surfacing is required, or when welding two separate cast iron parts together, preheating the product to 350 degrees is necessary. This method of welding cast iron is called semi-hot. The element to be welded can be placed in a forge with heat from solid fuel. After 20 minutes you can remove it and begin welding work.

An alternative heating method is a blowtorch (kerosene) or a burner with a propane-oxygen flame. Preheating the product will help smooth out the temperature difference between the material and the molten filler metal.

This will minimize the subsequent appearance of cracks and prevent the formation of cementites, which would complicate subsequent grinding of the seam. This method is used in cases where a high-quality connection is required that can withstand loads during operation.

To obtain the maximum effect from heating, it is necessary to ensure smooth cooling of the product after welding. At home, a cast iron part can be covered with ash from the stove or dry sand. The structure should be used only after it has completely cooled down.

Which electrodes to choose

To weld cast iron with an inverter, special electrodes are required, the wire composition of which will interact well with the base metal and prevent the release of carbon and the formation of pores. The following brands have proven themselves to be excellent in this regard:

• TsCh-4;
• MNC-2;
• OZCh-2;
• OZZHN-1.

Nickel and copper are added to their composition, which prevents the release of carbon. Additionally, the tensile properties of these admixtures contribute to a stronger weld that can withstand tensile and fracture loads.

If it is not possible to purchase electrodes for welding cast iron, and repair work cannot wait, then you can make them yourself. To do this, copper wire is wound onto conventional electrodes (E-46, ANO-21). The coils are laid tightly to each other in one layer.

It is necessary to start winding from the end of the electrode that will burn. The diameter of the copper wire does not matter and can range from 0.5 to 1.0 mm.

When an electric arc burns, the rod of the electrode itself and the wound copper melt, and the coating of the electrode will protect the weld pool from the external environment.

Device settings

In order to qualitatively weld a cast iron product at home, you need to correctly set the settings on the welding machine. Depending on the brand of electrode and its diameter, the current strength at the inverter is set according to the table below:

Electrode brand	Electrode diameter, mm / current, A	Electrode diameter, mm / current, A	Electrode diameter, mm / current, A	Electrode diameter, mm / current, A
MNC-2	3 / 90-110	4 / 120-140	5 / 160-190	6 / 210-230
TsCh-2	3 / 65-75	4 / 90-120	5 / 130-140	6 / 220-240
OZZHN-1	3 / 100-120	4 / 130-140	5 / 160-180	6 / 220-250
OZCH-2	3 / 90-110	4 / 120-140	5 / 160-190	6 / 220-230

These parameters are well suited for welding cast iron in the lower position. If a seam is required on a vertical pipe, the current value must be reduced by 15-25 A. This will prevent the molten metal from flowing down and will allow the formation of a seam.

Welding cast iron at home with an inverter: technology and marking of electrodes

Carrying out welding work with metal does not pose any particular difficulties. But when it comes to welding cast iron, not everyone can cope with this task, especially if an amateur takes on the task.

In this case, it is necessary to strictly follow the preparation and welding technology, otherwise the material can be overcooked, which will make it brittle or lead to other problems. Let's look at the welding process in more detail.

Electrode welding technology

Semi-automatic welding of cast iron is performed in accordance with the grade of material, its dimensions and the presence of defects. The brand of electrode for welding cast iron is selected differently in each specific case.

For example, if cold or hot welding of cast iron is used, then TsCh-4 electrodes are chosen. They are used to prepare cast iron for welding and allow 1-2 layers to be deposited onto the worn part of the part for subsequent surfacing with special rods.

OZCH-2 is most often used in the repair of thin-walled structures. They allow you to weld cast iron to remove casting defects. MNC-2 is also used to eliminate casting defects.

Welding cast iron at home is a task within the capabilities of every person. However, it is important to follow some guidelines. The person doing the work will also need to have certain skills. If such a procedure is carried out for the first time, then it may not work out right away.

During the production of cast iron, the temperature is maintained at a level of 1200°C – 1500°C. In this regard, high-temperature processing of this material is not possible, and its properties are determined by its carbon content.

Heating when welding cast iron.

In each of the noted methods of cast iron welding technology, the following rules should be followed:

1. Rapidly cooling the surface of the product is strictly prohibited.
   If you need to weld a part to metal, then you can increase the cooling time of the latter by filling it with sand.
2. In the liquid state, the metal becomes fluid, so it is necessary to use preforming.
3. Welding cast iron with the TIG method is associated with a number of difficulties.
   In particular, a firm seal of the seam must be ensured. The most labor-intensive operations include the process of joining heterogeneous products. In this regard, the parameters of each part should be taken into account in the work.

If it is necessary to make welding using a welding machine, certain brands of electrodes are usually used, available for purchase in hardware stores. There is also an alternative to rods in the form of welding wire.

Wire for welding cast iron with a graphite rod allows you to form a fairly reliable connection.

Regardless of the method, be it argon welding technology using semi-automatic or manual arc welding, you must adhere to the following sequence of actions:

• prepare the surface of the cast iron part by removing defects from it mechanically or manually;
• determine the grade of material;
• use a method that allows for the best connection, for example, in some cases metal studs can be used;
• welding work: this material can be welded using argon arc welding, but for this certain conditions must be observed;
• after completion of the work, the parts are covered with sand or other material that does not allow the product to cool quickly.

If everything is clear with the first point of the above list, then the second should be considered in more detail. The fact is that preparation includes not only mechanical processing, but also the determination of all possible procedures to be performed in the work.

First, the worker visually inspects the product and determines the resistance to thermal effects from the cut. Based on this visual inspection, welding modes are selected.

As for forming a reliable connection, you can use the method using studs. The essence of this technology is that studs are pre-installed into the part to strengthen it.

Scheme of surfacing when welding cast iron.

Further, during work, it is important to fulfill the following condition: a small amount of molten material should be constantly maintained in the weld pool, as well as its uniform mixing during operation.

Additives are also often used during the compound formation process. It may be necessary to use a mixture consisting of sodium nitrate, soda and technical borax.

If you follow simple rules, arc welding will not cause many problems and, if you have certain skills, will be quite simple. The main thing is to choose the right cooking electrodes. In some cases, it is worth giving preference to rods of the RDS brand, and in others - ESAB.

It is worth remembering that electric welding is most effective not only with the correct choice of electrodes for cast iron, but also with the correct determination of the grade of material. If you have the proper skills, welding and repairing the radiator of a cast iron battery will not cause any problems.

How to properly weld cast iron parts?

Cold welding of cast iron is a method of forming a joint on a material without heating. Welding cast iron with argon using this technology is carried out in cases where it is not possible to preheat the parts.

Influence of electroslag welding mode on the penetration size of cast iron.

The reason for this situation may be, for example, the size of the product is too large or the specific shape of the part.

Cast iron is welded using an electrode with a top layer of steel with a low carbon content. Stainless steel electrodes or copper electrodes are also often used.

When welding cast iron with an electrode at home, you should keep in mind that using an uncoated rod will not allow you to achieve a high-quality connection.

This is due to the heterogeneous composition of the deposited metal, namely, during the joining process, the lower layers will be enriched in carbon and will become close to cast iron, and the upper layers, on the contrary, will become low-carbon and closer to the metal.

You should not forget about the shrinkage of cast iron and steel, since it varies greatly for these materials, so you should not allow too large volumes of deposited material.

What to cut with?

The need to perform such a procedure is most often associated with the dismantling of cast iron pipes, heating radiators and other communications. At first glance, it may seem that performing this work will not cause much difficulty. However, in the Soviet Union the pipes were connected tightly, so cutting them is not so easy.

Argon welding of cast iron allows you to form reliable compounds of this substance with many others. For example, this could be welding cast iron with steel or aluminum. In any case, disassembling the welded structure is not easy.

The main thing here is to choose the right cutting method. You can use familiar tools such as a pipe cutter, chisel, jigsaw, gas cutters, and so on.

Each method presented has its own advantages and disadvantages. For example, in some cases you can easily get by with a regular hammer and chisel. Especially if the cast iron welding technology was violated and the formed connection turned out to be weak.

In other cases, it is better to use more productive mechanical, rather than manual, tools, for which electric arc welding of cast iron is not a hindrance.

Edge cutting

After cast iron electrodes have been selected, it is necessary to prepare the edges of the part for welding. First of all, you should take care of the cleanliness of the surface of the product, as mentioned earlier.

Next, before welding cast iron using electric welding, you should cut the edges. This is especially true for the repair of various devices. In such cases, cutting the defective areas is extremely necessary. It is carried out on one or both sides in an X-shape.

Welding steel with cast iron will be more reliable if, before starting work, a nickel additive is deposited on the edge of the latter. This will allow the formation of a so-called transition layer, which will have a positive effect on the quality of the seam.

Of course, the marking of electrodes for cast iron in this case will be different. Suitable options for connecting to steel would be rods of the TsCh-4, OZCh-2 brands.

Brands of electrodes for welding

Marking of electrodes for cast iron includes the following most common options: MNCh-2, TsCh-4, OZCh-2, OZZHN. There are other designations, for example, t590. This brand of electrode for cast iron is also capable of providing a high-quality connection.

Electrodes for welding cast iron are selected depending on the task being solved. For example, it has already been mentioned that it is better to connect to steel using TsCh-4.

It is worth noting that not only welding electrodes for cast iron give the best results. Acceptable quality can be achieved using UONI-13/55.

However, welding cast iron with an inverter using these rods requires some caution, since excessive heating can lead to the formation of cracks in the thermally affected area.

Results

Welding cast iron can be a challenge for any beginner. Nevertheless, it is enough to follow a few simple rules and observe the workflow technology, and then the welded joint will have good quality and reliability.

Source: https://tutsvarka.ru/vidy/svarka-chuguna

How to cook cast iron with an inverter - Forging, welding, blacksmithing

Cast iron is an alloy of iron and carbon, which cooks very poorly due to the content of the second component in a volume of 2% to 6% (steel has the same chemical composition, but it contains up to 2% carbon and it cooks perfectly). Scientists and engineers have developed technological processes that make it possible to weld cast iron using an inverter welding machine.

External view of the welding inverter “Stroitel 300R”.

Internal structure of the welding inverter “Stroitel 300R”.

Let’s begin the answer to the question “how to cook cast iron with an inverter” by considering situations in which the need arises for welding cast iron parts. And let’s figure out what is the difficulty of welding this alloy.

The need for welding cast iron and what is its complexity

Situations in which welding of cast iron is necessary are presented in the table.

In what cases is welding of cast iron required?

The process of welding cast iron parts is complicated by the fact that the welded joint (seam) may be of poor quality. This is caused by two reasons:

• in the weld area, intense hardening of the metal occurs, which already has low ductility. As a result, its fragility increases, leading to the formation of cracks during shrinkage of the weld;
• The welding process is negatively affected by the combination of oxygen and carbon with the subsequent formation of carbon monoxide. This causes the seam to become very porous.

Using an inverter for welding cast iron helps solve many problems. First, let's figure out which electrodes should be used.

What electrodes can be used to cook cast iron?

The peculiarities of welding cast iron parts with a welding inverter require the use primarily of electrodes based on the following metals:

How cast iron is welded with these electrodes is shown in the figure.

The procedure for filling cracks.

For welding cast iron with an inverter, special electrodes are used and it is very important to choose them correctly. Let's figure this out.

Electrodes of the TsCh-4 brand are used for:

• hot and cold welding of cast iron;
• sealing defects;
• repair surfacing.

The same electrodes are used for welding steel and cast iron. They allow you to deposit 12 layers on worn cast iron parts, preparing them for further surfacing with other welding electrodes.

Technical requirements for welding with an inverter using TsCh-4 electrodes (hereinafter referred to as requirements):

• welding is performed in the lower position of the seam;
• the process is carried out using reverse current.

Electrodes of the OZCh-2 brand are used for:

• cold welding of malleable and gray cast iron;
• elimination of casting and surfacing defects.

Requirements:

• welding is performed in the vertical and lower positions of the seam;
• the process is carried out using reverse current.

Electrodes of the OZCh-6 brand are used for:

• cold welding of malleable and gray cast iron;
• carrying out repair work on thin-walled products.

Requirements:

• welding is performed in the vertical and lower positions of the seam;
• the process is carried out using reverse current.

Electrodes of the MNCh-2 brand are used for;

• cold welding of cast iron;
• welding casting defects;
• surfacing on parts made of malleable, gray and high strength cast iron. The deposited metal has a high density. Therefore, such electrodes are usually used in the repair of critical objects that require high quality welds.

Requirements:

• welding is performed in vertical, lower and limited ceiling positions of the seam;
• the process is carried out using reverse current.

Parameters for welding cast iron with electrodes without heating.

Electrodes of the OZZHN-1 and OZZHN-2 grades are used for welding high-strength and gray cast iron with multi-layer welding of large defects and deposition of large volumes of metal. They are usually used in conjunction with electrodes of the MNC and OZCh brands: with the help of the latter, the first and last layers of the seam are made, and the intermediate layers are made with the help of OZZHN electrodes.

Requirements:

• welding is performed in the vertical and lower positions of the seam;
• the process is carried out using reverse current.

Electrodes of the OZCh-4 brand are used for welding high-strength and gray cast iron. They make it possible to deposit and weld the final layers of the surface, while ensuring wear resistance and high quality of the deposited layer, making it high-tech and impact-resistant.

Requirements:

• welding is performed in the vertical and lower positions of the seam;
• the process is carried out using reverse current.

Currently, there are other models and new types of welding electrodes are being developed that are used in welding cast iron. The quality of the weld largely depends on the correctly selected inverter and welding electrodes.

Preparing cast iron blanks for welding

Regardless of the brand of welding equipment used (inverter and electrodes) and the selected welding technology, the workpieces to be welded must be prepared. It consists in eliminating defective areas and processing the welded edges in a certain way.

Edge cutting options.

Defective areas of the workpiece should be cut to bare metal. The edges should be removed in such a way as to ensure the most comfortable working conditions. The following tool is used for processing:

• portable sanding wheel;
• scrapers;
• drill;
• rollers, etc.

You can use a bench chisel and use it to trim off the edges. To prevent chipping when using this tool, the metal should be cut in thin layers.

When preparing and cutting defective areas, the following requirements should be met:

• the operation is performed exclusively on the crack;
• To prevent an increase in the size of blind cracks during processing, holes are drilled at a distance of 10 mm from their ends. Their diameter should be 12 mm greater than the width of the crack;
• through cracks are cut from one or both sides (depending on the grade and thickness of the cast iron);
• The hole is sealed as follows:
  • edges are smoothed;
  • acute-angled protrusions are cut off using a chisel;
  • It is recommended to repair the hole in the following sequence. Using an emery wheel, the surface is cleaned to a distance of up to 30 mm from the edges of the hole. A patch is cut from low-carbon steel sheet. Its dimensions should be such that it covers the hole by approximately 1520 mm. In order to reduce the stresses arising in the metal during the welding process, the edges of the patch are beaded at 30°. The patch is placed with the flanged part on the cast iron and overlap welded;
• cracks located close to each other are sealed with a patch. The technology is similar to that mentioned above for repairing holes.

Methods of welding cast iron

Cast iron can be cooked in different ways. When choosing a method, in order to get a positive result, it is important to know the features of its welding. The main criterion when choosing a welding method is the quality of the resulting weld.

There are two types of cast iron welding:

The hot type of welding is used in enterprises that have the ability to heat the cast iron products being welded to the required temperature. This type of welding allows you to obtain high quality welds. But not everywhere it is possible to carry out such heating, and the cold welding method is used.

Hot welding of cast iron with an inverter

The advantage of hot welding is that there is no risk of cracking. During the welding process, uniform heating of the parts being welded should be achieved. The presence of a large temperature difference between the base metal and the weld most often leads to the formation of cracks and other defects.

When starting to heat the parts, they should be securely secured in a rigid frame (conductor). This form of bondage will allow you to get rid of stress, which during work can lead to the formation of cracks. A rigid frame may not be used if local heating of parts is used. Heating of workpieces is usually carried out in induction heating furnaces. If necessary, the following equipment can be used:

• forges;
• blowtorches;
• flame burners, etc.

If it is necessary to weld through cracks or eliminate defects that appear on the edges of the product, graphite molds are traditionally used. Such technological equipment prevents leakage of liquid metal.

Welding in graphite molds of bracket and gear.

The molds are made from graphite plates. To assemble individual parts into a functional structure, a molding mixture consisting of quartz sand and liquid glass is used. To minimize the risk of cracks, molds should be preheated and subsequently ensure uniform cooling

Cold welding of cast iron with an inverter

If the need to weld cast iron occurs infrequently, and you do not have special heating equipment, then you should use cold welding technology. It is carried out using a welding inverter and special electrodes:

• OZCH-2. It is a copper rod coated with a special composition;
• MNC-2. The rod is an alloy, which includes:
  • copper;
  • iron;
  • manganese;
  • nickel.

A technologically advanced and high-quality weld allows us to obtain MNCh-2 electrodes. But they have a high cost, and finding them is often not so easy. OZCH-2 electrodes are much cheaper, but the quality of the seam will be somewhat worse.

For cold welding of cast iron, homemade electrodes are often used when using an inverter. They are made as follows: copper or brass wire is wound onto an electrode for welding steel. Wire diameter Ø 1.52 mm. The length of the wire is determined by its mass: the wire should have 45 times more than the rod. This method is illustrated in the video at the end of the article.

Mode of cold welding of cast iron with an inverter

Welding should be carried out in the following mode:

• short arc;
• reverse welding current;
• Welding should be carried out with breaks to allow the metal to cool to a temperature T = +50°C;
• weld in small sections 3050 mm long and immediately forge.

Where will the service be provided?

• Website: http://svarka-luxe.ru/;
• Address: Moscow, 4th Grazhdanskaya street, building No. 33/1, building No. 7;

Source: https://kovka-svarka.net/2016/01/kak-varit-chugun-invertor/

Technology of welding cast iron with electrodes. Process description

For a home craftsman, welding work with steel does not pose any difficulties. But not every self-taught welder knows how to cook cast iron using electric welding.

Technology of welding cast iron with electrodes

There are 2 methods of welding cast iron - hot and cold.

Hot also includes semi-hot.

When hot joining, the part is heated to a temperature of 600-700°C, welding is performed and the cast iron product is slowly cooled in the furnace. With a semi-hot connection, the temperature is maintained at 300-400°C.

Hot and semi-hot welding requires additional equipment. In domestic conditions, a cold connection is used.

How to cold weld cast iron parts

When connecting, do not overheat the heat-affected area (no more than 80°C). Take frequent breaks between passes. Use multi-pass welding.

1. first perform surfacing along the edges of the chamfers;
2. then gradually filling the seam;
3. After each pass, hot forge the roller.

Make rollers 40 mm long, scattered to reduce heating of the part.

How to weld cast iron using electric welding at home. What you will need:

• current source (inverter);
• electrodes 3 mm;
• seam cleaning brush;
• hammer for forging and removing slag;
• cutter or cutter for cutting chamfers;
• shield and gloves.

The process itself:

1. first, cutting edges and blunting sharp corners;
2. then surfacing along the edges of the chamfers;
3. then gradually fill the seam.

Forge each roller hot. Don’t rush, give the part time to cool (heating of the heat-affected zone is no more than 80°C).

After filling the weld, turn the part over and cut the edges on the reverse side. Perform welding as described above. Observing the temperature regime and forging each roller. At the end of the process, grind the deposited surface if desired.

Cold welding is used to repair batteries, vices, engine cylinder blocks and other structures made of gray cast iron.

Brands of electrodes for welding cast iron

In this article, you can get acquainted with factory electrodes and homemade electrodes for connecting different types of cast iron.

The table below will help you set the current on the device for different diameters of electrode brands:

• TsCh-4;
• OZCh-2;
• OZZHN-1;
• MNC-2.

The current values ​​are indicated for the lower position of the electrode. For a vertical position, the current is reduced by 15-20 A, except for TsCh-2.

In order to save money, home craftsmen have adapted to welding cast iron with a conventional electrode with copper wire. below:

Also, copper wire will help in welding cast iron with steel.

Some craftsmen ask how to cook cast iron with a semi-automatic machine? On metalworking forums, experienced welders advise using PUNCH 11 wire. The connection is made with 2-5 cm stitches with forging, without gas protection on straight polarity. Current 90-110 Amperes depending on the thickness of the metal.

How to cut cast iron

Types of cutting are divided into thermal and mechanical. List of tools and methods:

1. The grinder is a simple and affordable way. Minus: the cut occurs in a straight line.
2. Pipe cutters have proven themselves well when working with pipes.
3. Reciprocating saw.
4. Electrode.
5. Oxy-fuel cutting is a good option. Oxygen flux will improve the quality of cutting cast iron.
6. Mobile installations Thermal cutter 2M (weight up to 5 kg).
7. Oxygen-lance cutting and plasma.

As you can see, there is plenty to choose from! The grinder is widely used in everyday life.

(3 3,33 out of 5)

Source: https://plavitmetall.ru/svarka/kak-varit-chugun-elektrosvarkoj.html

How to weld cast iron with an electrode at home

The service life of cast iron is twice as long as that of steel, however, due to the high carbon content, repairs by conventional electric welding of parts made of this material are ineffective. Microcracks form at the junction, and pores form at the seam. In industry, this problem is solved by special training, which is not applicable for welding cast iron at home. However, creating strong connections is also possible with self-repair using electrodes for welding cast iron.

Features of cast iron welding

It has been established that welding gray cast iron with a finely dispersed structure is easier to weld than coarse-grained metal of a dark shade. Parts that have been in contact with oil for a long time or have been subject to oxidation cannot be welded. Cast iron is a material with limited weldability, so its features are taken into account when working:

• due to the high fluidity in the liquid state, welding is carried out mainly in the lower position;
• formation of pores in places where carbon burns out;
• due to low ductility, when the temperature regime is violated, internal stresses arise, creating a crack in the seam;
• When melting, cast iron produces oxides with a melting point higher than its own.

Selecting electrodes for welding cast iron

When cold welding, inexpensive electrodes with an index of 2 to 6 are most often used. The basis is copper rods with a special coating. The MNCh-2 grade is used for surfacing metal; an alloy is used to make rods, to which nickel, manganese, iron, and copper are added. These electrodes are scarce and expensive. Cheaper ones include TsCh-4 and OZZHN-1.

Source: https://svarkaprosto.ru/tehnologii/svarka-chuguna-elektrodom

Welding cast iron with an electrode at home

When a car manifold bursts or cracks appear in cast iron pipes, you have to think about welding work. However, welding cast iron parts is much more difficult than conventional low-carbon steels.

The main defects of such welding are the pores formed on the surface of the weld. After welding, you can often hear the product begin to crack slightly. This indicates that microcracks have begun to form in the area of ​​the weld.

• We cook cast iron without leaving home
• Welding methods
• Selecting Electrodes
• Technological process of welding work
• Conclusion

In production, before starting to cook cast iron, which contains a lot of carbon, preliminary work is carried out. First, the workpiece is heated by induction currents. It is then left to cool naturally.

Cast iron products are often found in everyday life. How to cook cast iron using electric welding, how to weld a crack at home? An ordinary inverter comes to the rescue . In order for the connection to be strong and of high quality, it is necessary to prepare the product for welding and set its correct modes.

We cook cast iron without leaving home

As already mentioned, you can cook cast iron with an inverter, which can operate normally on direct current. It is also possible to use a welding transformer for welding. It is equipped with an additional converter capable of holding direct current. As a result, the base metal is well fused and a high-quality connection is obtained. When the arc is lit and welding is carried out, there is virtually no spatter.

Welding methods

There are several ways to weld cast iron products at home. When you need to weld a manifold crack in your garage or remove a sinkhole that has appeared on a part, you can use the cold option.

We are talking about welding work that is performed cold, that is, cast iron is welded without preheating. The area of ​​the workpiece that has become unusable is thoroughly cleaned. All oxides and accumulated dirt are removed.

When the width of the crack is less than 1 mm, it is first expanded using a grinder on which a thin disk is installed. The molten metal will fill the crack to its full depth, and the weld will be strengthened.

This type of cold welding is mainly used for joining parts that are not subject to heavy loads.

When it is necessary to fuse the teeth of a cast iron gear or connect cast iron products, the parts must be heated to a temperature of 350 degrees. This method of cast iron welding began to be called “semi-hot”. Cast iron parts to be welded can be heated in a forge, in which the heat is created by solid fuel. Cast iron blanks are kept in the furnace for about 20 minutes. Then they are removed with special forceps and welding work is performed.

You can heat the parts in another way. For this you will need:

• Blowtorch;
• Propane torch.

This preheating of the workpiece helps smooth out the temperature difference that occurs between the material being welded and the molten additives. As a result, the appearance of cracks becomes minimal. Virtually no cementite is formed , which becomes an obstacle to grinding the seam. This technique is used to create a high-quality connection that can operate under heavy loads.

To get the maximum effect from preheating the workpiece, it is required that the parts cool slowly after welding. Typically, such cast iron parts are covered with ordinary sand at home and wait until they cool completely.

Selecting Electrodes

To cook cast iron parts with an inverter, you must have special electrodes. They are made of special wire that does not allow large amounts of carbon to be released. An electrode made of such wire prevents the appearance of pores. The most popular brands of electrodes are:

• TsCh-4;
• MNC-2;
• OZCh-2;
• OZZHN-1.

The welding electrode for cast iron is somewhat different from conventional brands. To prevent the release of carbon, copper was specially added , together with nickel. These impurities have tensile properties. The result is a very strong seam that can withstand heavy loads.

When there are no special electrodes for welding cast iron at hand, and repair work needs to be done very urgently, you can make an electrode yourself.

Ordinary electrodes are taken, for example, E-46, on which copper wire is simply tightly wound. You should get one dense layer. Winding must begin from the end of the electrode intended for combustion. The cross-section of the copper wire should be in the range of 0.5 - 1.0 mm.

Technological process of welding work

In order to obtain a high-quality welded connection of cast iron parts in your garage, you must comply with all the requirements imposed by cast iron welding technology.

If the thickness of the parts is very large, the technology requires preliminary cutting of the edges , maintaining an angle of 45 degrees. This operation is easily performed with a regular grinder.

When it is necessary to weld a crack, it is deepened with a thin disk. The ends of the damaged area are drilled.

If the thickness of the material is less than 3 mm, a graphite base is placed under the part. It will prevent molten metal from flowing out from the opposite side.

Before starting welding work, the workpiece must be thoroughly cleaned. Remove all debris and accumulated dirt. Then the part must be heated in any suitable way. After reaching the appropriate temperature, the parts are welded. Heavy parts are fixed with tacks that hold the entire structure.

When the first seam is made, the movement of the electrode, according to the technology, should be fast and smooth. Its transverse vibrations are not allowed. If the joint length is more than 100 mm, it is better to apply the seam in two or three passes, starting from the opposite side. The result will be uniform heating of the part, and there will be no overheating of individual parts of the workpiece.

When it comes to welding thick cast iron, multi-pass welds are used. When the first layer is made , the electrode can perform oscillatory movements. Thus, a more reliable bond of metal occurs and the dimensions of the seam expand.

The slag must be separated continuously. It is knocked down after applying each layer. As a result the appearance of lack of penetration is eliminated , and pores that can form in the lower layer are blocked. When the welding work is completed, the parts are covered with sand. All you have to do is wait for them to cool completely.

Conclusion

You can cook cast iron with an inverter that produces direct current in your garage. You just need to purchase special electrodes and make proper adjustments of all parameters.

Welding should be carried out carefully, avoiding overheating of individual areas. Since cast iron is a very fluid material, welding it requires some experience. Therefore, before starting such work, you need to practice a little on other cast iron parts.

Source: https://instrument.guru/svarochnye/svarka-chuguna-elektrodom-v-domashnih-usloviyah.html

Welding cast iron with a conventional electrode at home

Durable and reliable - cast iron is one of the most common materials used in everyday life and industry. It has its undeniable advantages: it lasts a long time, is relatively inexpensive, can be easily welded, and does not lose its performance characteristics over time. When might it be necessary to weld cast iron with an electrode? If, for example, a seam in a heating radiator is leaking, it needs to be patched, or several more compartments need to be welded to the batteries.

Cast iron - types, application

Cast iron is a kind of mixture of iron and carbon. The material is hard and wear-resistant, but, paradoxically, quite fragile if not handled correctly. This is why welding cast iron with an electrode at home using an inverter should only be done after careful preparation (this will be discussed below).

Cast iron has been known in the world for a long time - it is believed that it appeared in the 6th century BC.

The average melting point is over 1000 degrees Celsius. You can work with the material when heated to 600 degrees.

By type, cast iron metal is divided into the following categories:

• white;
• half-hearted;
• grey;
• high strength;
• malleable.

Over time, cast iron does not lose its relevance; it is used in various spheres of human activity. The material is used for the following purposes and tasks:

• forging fences;
• production of machine tools;
• production of frying pans for household use;
• manufacturing of heating radiators, pipes, plumbing connections;
• creating baths;
• in the automotive industry - for the production of crankshafts, cylinders, engines and other things.

This is only a small part of the tasks that ordinary cast iron can successfully cope with. An important feature is that surfacing cast iron with electrodes can be done at home without the help of a professional welder.

Types of welding

To know how to weld cast iron with a conventional electrode, it is important to understand the types of welding in general. They are divided into:

• hot;
• semi-hot;
• cold.

Hot is indeed such, occurring at temperatures between 600 and 700 degrees Celsius. The metal is heated in industrial furnaces, which are considered heavy-duty equipment. Cast iron becomes flexible, like plasticine, and is easy to work with. During the process, no cracks or pores appear on the product that would interfere with normal operation in the future.

Experts call this welding method the most ideal for cast iron. Naturally, to the question: is it possible to cook cast iron using conventional electrodes at home using the hot welding method, the answer will be negative. Creating such a colossal temperature in an apartment or garage, for example, is dangerous to life and health.

Semi-hot welding is also impossible at home. It is carried out at a temperature of 300-400 degrees Celsius. For heating, special hair dryers or heating elements are used. This method is used in industry.

Its main advantage is faster cooling compared to the hot method.
For a novice master, the semi-hot technology of welding cast iron with electrodes is practically impossible. Cold welding is suitable for home use.

It occurs at a maximum temperature of 80 degrees Celsius.

Preparation for welding with electrodes

To begin the welding process, it is necessary to make thorough preparations for it. In particular:

• sand the surface;
• degrease parts of the unit without fail;
• prepare the welding machine, make sure that it is technically sound;
• decide how exactly the welding will take place: on studs or in multilayers;
• prepare a sufficient number of electrodes;
• remember the safety rules.

It is forbidden to start work if the surface is not cleaned and sanded - this creates the possibility of a dangerous situation: a sharp element will jump off during the welding process and cause injury to the worker. Simple electrodes will not work in this case. It is necessary to purchase those that contain chromium, copper and nickel.

You cannot start work without theoretical preparation for the process. Failure to comply with the technology will lead to the fact that when the material hardens, numerous pores and cracks will form, cast iron will lose its excellent performance properties, and it will simply be impractical to use it in the future.

Features of the welding process

Now we’ll tell you how to weld cast iron using electric welding. When the master is convinced of the reliability of the equipment, he can begin the process. To do this, you need to choose how to cook cast iron with simple electrodes:

• on studs;
• multi-layered.

In the first case, the master first installs the pins themselves, and forms a seam around them. Experienced welders recommend performing the procedure in a staggered manner to prevent overheating of the material. The work is completed with a connecting seam - it goes from one pin and its “surroundings” to the other.

The multilayer method is as follows: chamfers are created, then the initial layer is fused, it is hammered, then a second layer is laid, tapped again, and so on. After the seam has cooled, it must be sanded to give the product an aesthetic appearance. If it is possible to access the inside of the product, then the initial layer in the multilayer method is placed on the outside and inside. This makes the connection even stronger.

In general, there is nothing complicated about how to properly cook cast iron with electrodes. The main thing is to follow safety rules.

Safety precautions

Even before cooking cast iron with a conventional electrode, it is important to take care of following safety precautions:

• Place a fire extinguisher near your workplace;
• make sure the welding machine is in good working order;
• put on special protective gloves for welding activities;
• cover your face with a mask or at least glasses;
• work exclusively in thick clothing so that particles of hot metal do not have the opportunity to come into contact with the skin;
• it is important that fresh air always flows into the room where welding is performed;
• if you are welding for the first time, it is wise to invite an assistant or at least an outside observer, so that in case of an emergency, there will be someone to help.

Naturally, it is advisable to work during daylight hours or at least in sufficient lighting, in an absolutely sober and healthy state.

Interesting video

Source: https://osvarka.com/svarka-metallov/svarka-cuguna-elektrodom

Welding cast iron with an electrode at home using an inverter: which one, how to do it correctly

Cast iron is an alloy of carbon and iron, which also contains alloying additives and impurities. Cast iron parts are widely used not only in industrial and production areas, but also in everyday life. Cast iron products for private use: plumbing elements, fence structures, car parts and much more. The active use of this alloy leads to the need for welding work.

The main difficulties in welding cast iron that home craftsmen encounter:

• due to the fluidity of the alloy, it is recommended to carry out welding in the lower spatial position;
• non-compliance with temperature conditions leads to overheating of cast iron, which can cause the formation of pores and stress in welds;
• cast iron in a molten state can release gases , which will negatively affect the quality of the connection;
• Accelerated or uneven heating or cooling can promote cracking .

In order to obtain a high-quality connection of cast iron products at home, it is necessary to take into account these specific characteristics, as well as correctly prepare the working surface, select the correct welding mode and electrode.

How to cook cast iron with an inverter and a consumable electrode

Welding cast iron using an inverter and a consumable electrode is most often carried out using the cold method. Important components of successful work are: the correct choice of electrode and optimal welding modes.

Electrodes OZCH-3

The performer must make the connection with special electrodes containing nickel and/or copper:

• OZZHN-1;
• OZCh-2;
• OZCh-3;
• OZCh-4;
• OZCh-6;
• MNC-2;
• TsCh-4.

Recommended welding modes for some of the listed brands:

Electrode brand	Current strength for an electrode with a diameter of 3 mm.	Current strength for an electrode with a diameter of 4 mm.	Current strength for an electrode with a diameter of 5 mm.	Current strength for an electrode with a diameter of 6 mm.
TsCh-4	65-80	90-120	130-150	–
OZCH-2	90-110	120-140	160-190	220-250
OZZHN-1	100-120	130-150	160-180	–
MNC-2	90-110	120-140	160-190	210-230

The following technological features should also be highlighted:

• the length of one continuous seam should not be 30-50 mm;
• frequent breaks in the welding process will help eliminate the possibility of overheating; temperatures above 80°C are unacceptable;
• polarity is reversed.

This welding method can be performed in two ways: using studs and in layers.

1. The studs are equipped with threads, which allows them to be screwed into the edges of the product being welded. The studs should be staggered/staggered to prevent overheating during welding. The dimensions of the studs depend on the thickness of the workpiece; when selecting them, you should rely on the following recommendations:

• diameter – 0.3-0.4 product thickness, but not more than 12 mm;
• screwing depth – 1.5 times the diameter of the stud, but not more than half the thickness of the product;
• the height of the protruding part of the pin is 0.75-1.2 times the diameter.

After installing the studs, you can start welding. Metal is deposited around each pin, layer by layer. Then the performer needs to weld the space between the studs, which remains untouched, and make one or more connecting seams.

2. Multi-layer welding is performed after cutting the edges. The presence of sharp corners is not allowed. Surfacing should be done from the edges. The first layer is the main one, so during its deposition you need to carefully monitor the welding mode. Each subsequent layer, except the first and facing ones, must be forged with a hammer, without cooling.

The following video demonstrates the Zeller 855 cast iron electrode, but from the video you can see how welding is done.

This information will help the contractor learn how to cook cast iron with an inverter using electrodes on cast iron, and easily carry out the connection work.

Welding with conventional electrodes

In order to save money, you can use ordinary (steel) consumables instead of special ones. General purpose electrodes have a more affordable price.

The technology of multilayer welding with conventional rods is practically no different from the method discussed above, which uses special rods coated with non-ferrous metals. The stages of work are similar.

The only difference is that the layers following the first are deposited not with a special electrode, but with a regular one.

Attention! Welding cast iron with electrodes not intended for this purpose is possible, but we do not recommend using it in any critical connections! This information is provided only for welding for experimental purposes.

Welding with cast iron electrodes

This welding method can be carried out using a cold or semi-hot method. A little preheating will improve the structure of the weld metal.

Cast iron electrodes are cast rods coated with coating, used to correct defects in cast iron. This type of consumables includes the following brands: MNCh-1; OZCh-1; OZB-2M.

Welding is carried out using direct and alternating current.
The current value is determined as follows: 50-60 A per 1 mm. electrode rod. [ads-pc-3][ads-mob-3]

Welding with non-consumable electrodes

Welding cast iron using this technology is carried out in a protective environment of argon or fluxes, the main component of which is borax. Cast iron or special rods containing nickel, aluminum and copper are used as filler materials. Welding cast iron is carried out using tungsten, carbon and graphite electrodes.

The most common method is argon arc welding (AC TIG). In order for the work to be successful, you should adhere to several rules:

• Thorough cleaning of the surface from debris and dirt;
• the workpiece must be fixed at several points;
• It is recommended to use slight preheating of the product; for this you can use improvised means. It should be remembered that the presence or absence of heating depends on the type of cast iron being welded;
• the additive is supplied at an angle of 20-30 degrees;
• it is necessary to use small amounts of current;
• the connection should be carried out in stages : the performer welds a small section of 2-3 cm and forges the deposited metal so that
• avoid residual stress. Forging is done with a small hammer, the weight of which does not exceed 1.2 kg, the hammer is of a rounded type.
• Cooling of the part after welding is carried out gradually .

This method is not the main one when connecting cast iron products. This is due to certain difficulties that arise during the work process, as well as an increased level of labor and financial costs.

DIY electrodes for cast iron

In the absence of special electrodes for welding cast iron, you can independently make consumables that are similar in characteristics to the OZCH-2 and OZCH-6 grades. Next, we will look at two ways to make electrodes for cast iron with your own hands.

1. The production of electrodes for cast iron is carried out using the following technology:

Warning! We have not yet tried this method in practice, it was found in open sources, we are not responsible for the result. If you do, it is at your own peril and risk. Please share your results in the comments to this article. The next method is more traditional and has been tested by many, as shown in the video below.

• It is necessary to take copper wire with a diameter of 2-5 mm, sand it with sandpaper, degrease it and cover it with homemade coating;
  The easiest way is to prepare a coating from the coating of conventional electrodes (ANO-4, UONI-13/55).
• The coating of general purpose consumables is scraped off the rod, crushed and mixed with steel filings or iron powder in a 1:1 ratio. Then silicate glue is added to the resulting mixture, after which all components are thoroughly mixed.
• The wire is lowered into a homemade coating until the applied coating thickness is 1.5-2.0 mm. Then you need to wait until the excess mixture drains.
• The next stage is drying, which is carried out in the open air; the electrodes are dried in a vertical position.
• The final procedure - calcination is performed in the oven or on the stove at a temperature of 200-250°C.
• Homemade electrodes for cast iron are ready for welding. The welding mode with self-made electrodes does not differ from the operating mode with branded consumables.

2. There is another way to make a cast iron electrode. The welder will need a drill, a steel electrode (ANO-4, UONI-13/45) and copper wire with a diameter of 2 mm.

To make an electrode for cast iron with your own hands using this technology, you should perform the following steps: the wire is wound onto the steel base of a conventional electrode by rotating it clamped in the drill parton. To visually familiarize yourself with the production process, we recommend watching the video.

Do-it-yourself cast iron electrodes will allow you to save money and also perform welding work without downtime. But the quality will be lower than from using special electrodes for cast iron.

Making electrodes at home using cast iron can be done by a performer of any level.