How to weld cast iron and steel

How to weld cast iron to metal using electric welding

31.12.2018

When carrying out repair work, situations arise when it is necessary to connect dissimilar metals. Is it possible to weld cast iron and steel? Yes, but this can be done by people with experience.

Cast iron alloys are characterized by a high carbon content; when it burns out, the structure of the metal changes. The joint is boiled at low temperature, up to 120°C. Steel, on the contrary, needs to be very hot.

A buffer layer technology has been developed to connect cast iron parts with other ferrous alloys. Nickel alloy provides a strong connection between dissimilar metals.

Technology of welding cast iron with steel using a consumable electrode

There are several methods of welding cast iron; they are used to join cast iron alloys with other metals:

1. Hot - before joining the parts, the ovens are preheated to 600°C completely. Heating with a blowtorch is allowed only in the work area (cast iron becomes crimson in color). Used for reliable connections.
2. Semi-hot, good for alloys. The parts to be joined are partially or completely heated to 200–300°C.
3. Cold - parts are connected without heating, used for overlays - seams working under compression.

Joining metals by manual electric welding involves preliminary preparation of surfaces. Cast iron alloy is porous and absorbs oil well. It is not enough to degrease the stain; it must be cleaned to a clean layer, otherwise the seam will turn out loose.

How to weld steel to cast iron:

1. First you need to select the current parameters. If the welding machine only works on constant, switch the Polarity to reverse. It is necessary to take into account the no-load indicator (voltage between the poles without an arc), the permissible value is up to 54 V. Operating on alternating current is allowed only with no-load from 54 V.
2. Welding is carried out in small sections, the beads are made no more than 3 cm long. First, cast iron is deposited, then a steel part is welded to the buffer layer.
3. Thick-walled seams are welded in multi-layers, each one is hammered before applying the next. It is made perpendicular to the first - this is how the strength of the connection is achieved.
4. After joining the cast iron alloy with steel using hot and semi-hot methods, it is important to observe the cooling regime of the surfacing zone. The seam is periodically heated so that it cools gradually. When suddenly cooled, the cast iron alloy cracks due to internal stresses.

Selecting Electrodes

They use special ones that have:

• easy ignition at startup;
• low melting ability;
• high deposition rate;
• the hardness of the resulting roller.

Russian-made brands:

• TsCh-4 – multifunctional with cellulose coating, characterized by stable combustion and good deposition;
• OZCh-2, OZCh-25 – used for welding thin-walled elements, they do not burn through metals to a great depth;
• MNCh-2, OZZHN-2 are used only for the hot method of joining cast iron parts with metals.

Imported, used for critical seams:

• Zeller 866, Zeller 855 – universal, they are used to cook cast iron and iron without preheating;
• Ficast NiFe - create connections that work stably in bending and torsion.

Important!

Before work, it is important to dry the electrodes well and warm them up; they are heated from 160 to 300°C. But only a few pieces are taken from the pack - when repeated drying and heating, the coating will crumble.

Applications of argon arc welding

The use of refractory electrodes and copper-nickel filler wire gives good results.

How to weld steel to cast iron (several recommendations):

1. The additive is selected according to the type of metal and type of cast iron. Nickel-based flux-cored wire is most often chosen; the coating is first removed from it.
2. Argon is used as a protective atmosphere; it saves the seam from oxidation.
3. Refractory tungsten electrodes are chosen for work.
4. To work with thin-walled elements, experienced welders use small thin pieces of cast iron instead of wire.
5. For connections that experience only static loads (compression), nickel alloys can be used. They adhere perfectly to any grade of steel.

Important points in the welding process of cast iron and steel

1. Work is done in a low position.
2. The roller is made quickly without creating a wide melt pool.
3. Gray cast iron cooks worse; it must be heated, then a nickel-containing layer is deposited. Then the connection will be strong.
4. With alloy steels, cast iron forms a loose seam; it must be forged well.
5. The seam should be welded evenly, without sudden vibrations with the holder.

How to weld cast iron to metal using electric welding Link to main publication

Source: https://svarkaprosto.ru/tehnologii/kak-privarit-chugun-k-metallu

Cast iron - electrodes and welding with steel

I have to repair the UAZ gearbox and, in the future, the tractor engine block. In connection with this, the question is: what are the features of welding cast iron?

Example of a weld in cast iron

The alloy you specified is a rather difficult material, because...
contains from 2.14 to 6% carbon (everything below 2.14% is called steel). High carbon content negatively affects its weldability. As a melting method, manual arc (MMA) or semi-automatic welding (MIG-MAG) is best suited. When choosing an inverter, consult with store specialists, they will help you choose the right option.

Now, actually, about the features of cast iron:

• it has high thermal conductivity - accordingly, it very quickly releases the heat transferred to it. Rapid cooling leads to the appearance of hardening areas in the weld area and the formation of white cast iron prone to embrittlement.• Lack of ductility creates internal superstress in the structure• Carbon burns intensely when heated and melting, releasing carbon monoxide, which promotes the development of pores and cavities.

• Cast iron oxide is very refractory

Electrodes for cast iron

For RDS (MMA) the following are used:

• cast iron is now rare. They can be very large in diameter from 6 to 15 mm. It is recommended to use electrodes with a minimum diameter and at low currents.• copper based,• nickel based

• steel.

Application of steel electrodes

For cast iron, you can't imagine anything worse. It is advisable if minor defects are being repaired and no further machining is planned. The bleaching process causes the seam to become pliable and brittle. TsCh-4 electrodes are used, the rod of which is made of pure Fe or UONII-13/45, which are used for welding “black” and low-alloy steels

The best characteristics are shown by nickel-based electrodes (ESAB electrodes OK 92.18, OK 92.58). They carry out cold welding of cast iron (see below), but slight heating to 40 degrees is recommended. The resulting seam has good strength characteristics and can be processed with a cutter or milling cutter without restrictions.

Cast iron is welded well with copper-based electrodes, but you will not get the strength properties of the weld and heat-affected zone, this is due to the fact that Cu and Fe do not interact with each other until the Cu dissolves.

For semi-automatic welding

steel, nickel and silicon-bronze wires are used in combination with shielding gas or its mixtures.

Distinguish between hot and cold welding

• During hot welding, cast iron is heated to a temperature of 250 to 650 degrees, followed by melting at low currents. Overheating and high currents can lead to cracking. After the welding operation, the cast iron is slowly cooled. To do this, it can be placed in sand or covered with thermal insulation material.

• Cold welding for cast iron is carried out without heating, but you need to make the seams as short as possible, it is necessary that they cool gradually.

Read Repair of cast iron products by welding. From the experience of Uralmashplant.

Makita anti-splash sander

The welder may encounter “plenty” of spatter. In this case, stripping to a depth of more than 0.5 mm should help. The fact is that in the manufacture of the sand-clay mold into which cast iron is cast, not only sand and clay are used, but also binding components, including rosin. When heated, these impurities may enter the surface layer, and they “gas” when heated. Use a Makita sander with a sanding or roughing wheel to remove the surface layer.

Welding cast iron and steel

Hello, I am making a fence with a foundation in the form of a strip. Every 2.5 meters there are metal gratings that will be between the stone pillars. Cast iron sewer pipes were found to reinforce the stone columns. The grids in the posts will be secured with steel strips. Question: how to weld steel to cast iron?

Typically, before welding, steel and cast iron workpieces are heated to a temperature of 600 degrees. Preheating allows you to obtain continuous, hermetically sealed welded joints in one pass. But if, as in your case, preheating in a furnace is not possible, then the technology is changing. Weld the fence using rollers no longer than 25 mm.

Before surfacing a new bead, you must wait until the previous bead has cooled completely. That is, the base metal of the connection cannot be overheated. Also, the weld obtained in this way cannot be subjected to mechanical processing, since it has increased fragility. But there should be enough strength to maintain the integrity of a structure such as a fence.

To obtain a less brittle welded joint and a more durable seam, use electrodes for welding cast iron - as well as cast iron and steel - ESAB OK 92.58.

Source: http://svarka-master.ru/svarka-chuguna/

How to weld cast iron to metal with a simple electrode?

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.

Conclusion

In general, the process of how to weld cast iron with metal with an electrode is described above. Experienced welders will tell you the details and subtleties. Don't hesitate to ask them for advice. When working at home, choose the cold method. Work only with proven equipment, do not forget about safety precautions.

Interesting video

Source: https://varimtutru.com/kak-privarit-chugun-k-metallu-prostym-elektrodom/

How to weld cast iron to metal

Cast iron is one of the most popular metals for making a variety of products: from car parts to water pipes. At its core, cast iron is carbon and iron, which in the right proportions form a very strong and durable metal. Cast iron parts can be found in factories and industries, and even old cast iron frying pans have served their owners for decades.

Despite many alternatives, cast iron is not slowing down and remains a very popular material. Therefore, a home or professional welder will sooner or later have to face the need to weld cast iron. In this article we will tell you in detail what features this metal has, how to weld cast iron correctly and how to carry out welding work on cast iron with maximum benefit.

Features of cast iron

Welding cast iron in a garage or in large-scale production has a number of nuances that need to be taken into account before starting work. There are not many of them, so we will tell you about them all.

Welding cast iron must be done in the lower position, since the metal is very fluid. Do not overheat cast iron when welding, otherwise pores are guaranteed to form, followed by cracks. Also, when melting, cast iron releases a special gas, which negatively affects the formation of the weld. Therefore, welding of cast iron parts must be carried out quickly and in compliance with the temperature regime. Do not overcool hot cast iron, otherwise cracks will form again.

In order to get a truly high-quality welded joint when working with this metal, take into account all the features and characteristics of the cast iron itself. Be sure to prepare the metal before welding, select the correct operating mode in your welding machine and use special electrodes. But we will talk about all this further; first, we will deal with the preparation of the metal, since this is where the technology of welding cast iron begins.

Preparatory stage

The preparatory stage is one of the most important, since the quality of further work depends on proper preparation. First, clean the surface of dirt, dust and corrosion (if any). Degrease the metal with acetone.

If you are welding thin cast iron, make sure you have a heat-dissipating pad in advance. Cut the edges using a file or grinder.

 If you have to weld cast iron parts using the hot method (a method in which the part is heated before welding), then use a stove or gas burner for this.

Inverter welding with consumable electrode

Now let's move on to welding methods. Cast iron is cooked at an average temperature, so it can be welded with an inverter machine right in the garage or at the dacha, not to mention the factory workshop.

Welding cast iron with an inverter is carried out using a consumable electrode, as well as with a welding machine and a cold method (a method in which the part is not heated in a furnace or manually using a torch before welding).

Consumable electrodes must contain nickel or copper. Below you can see a table with recommended settings for different electrodes.

It is allowed to make intermittent seams, but not shorter than 3 centimeters in length, you need to use a temperature of no more than 80 degrees Celsius and allow the cast iron to cool. Also set the polarity to reverse.

Welding with steel electrodes

Is it possible to weld cast iron with ordinary steel electrodes? You can of course try, but we don't recommend doing it, especially with arc welding. Yes, standard steel electrodes are cheap, but such a connection will be unaesthetic and short-lived. If you need to weld a critical part (for example, part of a water pipe), then it is better to use special electrodes and do not skimp.

Welding with cast iron electrodes

For cast iron, specialized cast iron electrodes are best suited. You can cook it either cold or hot, as you see fit. We often warm up the part before welding so that the metal structure becomes better and the seam is more reliable.

Using such electrodes, you can easily correct multiple defects in cast iron, such as cracks, holes or chips. Electrodes of the MNCh-1, OZCh-1 or OZB-2M brands are often used in work. They are not that expensive, but the quality of work is excellent.

Welding cast iron with an electrode at home is carried out using direct and alternating current. To correctly set the current value, look at how long your electrode is. 1 millimeter of electrode corresponds to 50 amperes.

Welding with non-consumable electrodes

Welding of cast iron parts with non-consumable electrodes is carried out in a shielding gas environment or using drill fluxes. Nickel, copper or aluminum filler wire can also be used. Carbon, tungsten or graphite rods are used as a non-consumable electrode.

In most cases, when using non-consumable electrodes, cast iron is welded with argon (so-called TIG welding). We recommend slightly heating the part before welding using a gas torch. Set the welding current to a small value. Welding should be intermittent, 3 centimeters at a time. After welding, you need to gradually cool the part and monitor the temperature to prevent overcooling and the formation of cracks.

Welding cast iron with argon is rarely used, since it requires not only an electrode, but also a gas cylinder, preheating of the part and careful cooling, and all this takes a lot of time. Also, semi-automatic welding of cast iron is more expensive than other methods, but when you have no other option, you can weld using this method.

Gas welding of cast iron

Gas welding of cast iron is a fairly popular method, since the work requires only flammable gas, oxygen, cast iron welding wire and flux. At the same time, the quality of the seams is very decent. Welding wire for cast iron used in the work must contain flint. This is very important because silicon promotes the formation of graphite in cast iron and does not bleach the metal. You can also use low alloy cast iron wire for better weld quality.

The use of fluxes when gas welding cast iron is simply necessary, especially if you are welding steel with cast iron. Cast iron and steel are generally very different metals, so an oxide film forms on the surface in large quantities.

Instead of a conclusion

Welding cast iron with an electrode at home requires the master to follow the technology and take into account all the nuances of the metal itself. Take your time while working, use quality components and practice as much as possible. This way you can gain experience. Leave your comments and share this article on social networks. Good luck!

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Source: http://ooo-asteko.ru/kak-privarit-chugun-k-metallu/

How to weld cast iron and steel? Electrodes used

Carrying out construction work or various restoration operations often involves the need to weld various metals. A typical example is steel and cast iron.

In fact, these metals are close to each other in chemical composition, the main difference being the percentage of carbon. This moment complicates the work.

The second nuance is that carbon inclusions in the structure can be represented by granules of various sizes. If they are small, then the process does not cause any particular difficulties, but in a situation where the granules are large it is very difficult, even if visually the seam seems uniform, correct and reliable, great strength cannot be achieved.

So, let’s figure out how to weld cast iron with steel using electric welding, what technological requirements must be observed, and whether there are any effective alternatives for the connection.

Basic techniques

There are several of the most effective technologies:

1. Hot method . Before starting work, both parts are heated to 600 degrees. Local heating using a blowtorch is allowed. You can determine whether the desired temperature has been achieved by the fact that the cast iron turns crimson in color. Quite long, heavy, but the most reliable method in terms of strength.
2. Semi-hot technology is based on heating up to 200-300 degrees. The optimal choice for high alloy alloys.
3. The cold method does not involve preheating. It is simple to implement, but can be used exclusively when forming a weld, that is, a weld that functions in compression.

Welding cast iron with steel is complicated by the structural features of the first material. The top layer is not very dense, and therefore the part needs preliminary preparation. It is not just degreased, but cleaned until a clean layer appears.

If this requirement is ignored, the finished seam will be loose, porous and fragile.

Working instructions

Let's move on directly to how to weld cast iron to metal:

1. The necessary parameters of the electric current are set. Operation is carried out at direct current with reverse polarity - this is the case if the open circuit voltage does not exceed 54 V. If the open circuit voltage is above 54 volts, then the connection is made with alternating current.

The work is being carried out gradually, in small sections. The maximum permissible roller length is 30 millimeters. First, the cast iron part is processed, and the steel product is attached to it.

2. If a seam of large thickness is formed, then it is welded gradually, and it is necessary to forge it before making subsequent layers. Forging is carried out using a hammer, the fresh seam is compacted until it begins to emit a characteristic ringing sound.

The direction of the seams is different, that is, the second one is made perpendicular to the first. This allows you to achieve sufficient strength characteristics.

3. If welding with an electrode is carried out using a hot or semi-hot method, then sufficient cooling of the surfacing zone should be ensured. The seam is heated periodically to prevent its rapid cooling.

A sharp drop in temperature will cause thermal stresses to arise inside it, which can provoke both deformation and destruction.

Watch the video showing the technology of welding cast iron with steel using TsCh-4 electrodes (cold technique):

This video shows how to weld a steel bolt to a cast iron piece using copper wire:

Argon arc technology

The connection of these types of iron is also possible using the argon arc method. To achieve a high-quality result, you must adhere to a certain set of recommendations:

• The choice of additive is an important point. The exact grade of additive depends on what type of cast iron is involved in the process. The most widely used is nickel-based flux-cored wire, from which the coating has been previously removed.
• Argon is a gas that forms a protective atmosphere that prevents oxidation of the weld.
• The best working elements are electrodes made of tungsten, a refractory metal.
• If the surfaces to be welded are of small thickness, then an alternative to nickel is thin cast iron plates.
• If the weld will be subjected exclusively to static loads (compression), then a nickel alloy is the best option. This metal adheres well to all types of steel, regardless of grade.

Source: https://plavitmetall.ru/svarka/chuguna-so-stalyu.html

Methods of welding cast iron in production and at home

Cast iron is an alloy of iron and carbon. Unlike steel, cast iron is more porous, brittle, hard, and the thermal conductivity and coefficient of thermal expansion of cast iron is lower. Its use is based on these properties. Cast iron is widely used in the manufacture of cast products, which must have sufficient strength, heat resistance and consistency of shape and size. These are various pulleys, rollers, corrosion-resistant pipes, and manifolds.

Due to the fragility of cast iron, there are frequent cases of protruding elements of parts breaking off or simply splitting of products. When repairing such damage, welding can be successfully used.

Properties of cast iron alloys

carbon in cast iron exceeds 2.14%. This is precisely the borderline state of transition of carbon into the form of austenite, that is, into a state where, at a concentration less than indicated above, it is dissolved in iron. This phenomenon is used in the manufacture of steels.

In cast iron, carbon is found in the form of tiny undissolved particles, which determine its hardness and wear resistance, as well as its immunity to aggressive environments.

There are several types of cast iron depending on the chemical composition - white, gray, high-strength and malleable.

White is practically impossible to process with cutting tools due to its hardness and brittleness. Ready-made cast iron parts are cast from it, which do not need to be processed.

Gray cast iron tolerates static loads very well and is wear-resistant, but does not work well in tension and resists impacts. This cast iron welds better than all others.

Ductile iron, as the name suggests, is used in heavily loaded structures.

Malleable cast iron allows the creation of a hardened outer layer on the surface of parts, allowing this type of cast iron to withstand significant bending loads.

Welding difficulties

The structural features of cast iron determine a number of problems that arise when welding this material.

Due to the chemical composition of cast iron, when melted it becomes very fluid. This prevents the creation of a uniform seam, since the metal tends to flow out of the weld pool during prolonged heating.

Due to the low ductility of cast iron and low melting point compared to steel, cracking of the material is possible during rapid cooling after exposure to an electric arc.

The presence of a large amount of carbon, which is released when heated and interacts with oxygen contained in the air, contributes to the formation of large pores in the welding zone, causing the weld to be heterogeneous and have low resistance to bending load.

Knowing these features, you can organize welding work in such a way as to obtain a weld of satisfactory quality. To eliminate the effects of material fluidity, graphite plates are placed under the joint of the parts being welded, which prevent molten cast iron from leaking out during accidental burning.

After finishing welding the joint, the material should not be allowed to cool quickly. This requirement is especially relevant when welding cast iron and steel, when, for example, steel pipes are welded to cast iron radiators. Steel cools faster and therefore, in order to equalize the cooling rate of the two parts being connected, the steel is covered with coal or sand so that it retains heat longer.

The third problem can be solved by using welding in an inert gas environment. You can cook cast iron by electric welding using, for example, carbon dioxide, which displaces air from the weld pool. It is allowed to use a mixture of carbon dioxide and argon in a proportion of ¼.

Three ways

The connection of cast iron parts can be made, depending on the purpose, in three ways:

• cold;
• semi-hot;
• hot.

The cold method is used when welding non-essential joints, welding metal onto worn or abraded surfaces of cast iron. Welding is carried out at ambient temperature, and the welding speed must be high enough to prevent overheating of the joint and the consequences of its rapid cooling. This method is available for use at home, without the use of additional equipment.

The semi-hot method is used when welding parts that must subsequently experience mechanical stress. The essence of the method is that the part is preheated to a temperature of 300-350 °C, and this is only possible in specialized furnaces. This allows the cast iron to more easily “adapt” to the high temperature of the arc. As a result, the number of cracks in the heat-affected zone decreases.

In the case of the hot method, the workpieces for welding are heated to a temperature of about 600 °C. For such heating, devices that create induction currents are used. The temperature is controlled using instruments.

When the required temperature is reached, the parts are welded, after which they are left to cool, covered with hot ash. The cooling process can take several hours. The duration depends on the brand and thickness of the material being welded.

Technique

In everyday life, semi-automatic welding of cast iron is most popular, as the most affordable and simplest type of connection. In this case, thin parts must be welded, making sure to place graphite plates under them.

For welding, you can use almost any semi-automatic machine that allows you to use the welding current necessary for melting cast iron, but does not allow penetration and leakage.

The welding current ranges from 90-110 Amps. The speed at which the welding wire is fed is adjusted experimentally. As a rule, it is similar to the feed rate when welding steels.

Preparing parts

Before starting work, it is imperative to prepare the surfaces of the edges to be joined. To do this, they are cleaned of dirt and dust and degreased. To ensure greater depth of boiling, the edges are chamfered. The edges of the chamfer must be rounded.

If there is a need to weld a crack, it must be “cut” along its entire length in order to increase the area of ​​contact between the part and the welding material. This can be done with a grinder with a cutting abrasive wheel for metal work. Before welding, the ends of the crack must be drilled so that when heated it does not spread to an even greater length.

How to make a seam

To minimize the harmful effects that can be caused by a high-temperature arc to cast iron parts, long seams cannot be welded in one pass. The welding time on a separate short section of the joint should not be long.

You need to start welding from the middle of the joint and make a short seam, then step back some distance from it and make two more seams on both sides of the first. If the joint is of sufficient length, it is necessary to make several more short seams in the same way. Then the areas between the sutures are welded.

The first seam when welding parts of large thickness is placed in the middle of the joint, with virtually no transverse movements of the electrode. Next, the second and third are applied along the edges of the first seam.

If the thickness of the part still allows sutures, a fourth seam is applied in the middle, on top of the second and third, and later, after cooling, the fifth and sixth seams are applied to the right and left of the fourth. The specified sequence of seams is used further if it is necessary to make more seams with a sufficiently large thickness of the workpieces being joined.

Materials used

When it is necessary to connect workpieces using electric welding, special electrodes are used for welding cast iron, the coating of which must necessarily contain ferrosilicon.

This material allows you to achieve uniformity of the seam when welding gray cast iron. With sufficient qualifications of the welder, it is possible to obtain a seam that can be mechanically processed, giving it a more attractive appearance.

The most common brands of electrodes are:

• TsCh-4 - used more often than others. Thanks to special components capable of reacting with carbon, which produces carbides that are insoluble in iron, the coating of these electrodes allows you to obtain a high-quality seam;
• TsCh-3A – electrodes made of steel wire with a calcium fluoride coating applied to it. Thanks to this coating, a strong weld without cracks is obtained;
• EMChS - electrodes made from low-carbon steel wire with a three-layer coating of an alloying, gas-protective and slag-forming layer. Such electrodes are used for welding cast iron parts of small thickness (up to 10 millimeters).

When welding cast iron in an environment of inert gases or with non-consumable electrodes, it is allowed to use wire for welding cast iron, the grades of which are designated PP ANCH-1, PP ANCH-2, PP ANCH-3.

Each type of wire is designed for one of the welding methods - cold, semi-hot or hot. The wire is made in the form of a hollow metal tube, inside of which there is flux. This wire allows you to produce full-fledged seams that are not inferior in strength to the cast iron from which the parts being connected are composed.

With the correctly chosen welding method and sufficient qualifications of the welder, damaged cast iron products can be restored with virtually no damage to their previous condition, and their operation is possible for a long time.

Source: https://svaring.com/welding/soedinenie/svarka-chuguna

How to weld steel and cast iron - Do it yourself

Carrying out construction work or various restoration operations often involves the need to weld various metals. A typical example is steel and cast iron.

In fact, these metals are close to each other in chemical composition, the main difference being the percentage of carbon. This moment complicates the work.

The second nuance is that carbon inclusions in the structure can be represented by granules of various sizes. If they are small, then the process does not cause any particular difficulties, but in a situation where the granules are large it is very difficult, even if visually the seam seems uniform, correct and reliable, great strength cannot be achieved.

So, let’s figure out how to weld cast iron with steel using electric welding, what technological requirements must be observed, and whether there are any effective alternatives for the connection.

Let's sum it up

Connecting cast iron and steel elements is a completely feasible task. The main thing is to adhere to the above tips and recommendations.

An important point is that with an increase in the degree of alloying of steel, the friability of the weld also increases. To achieve the required strength, careful forging and compaction are required.

(15,00 out of 5)

Source: https://vsesamado.ru/kak-svarit-stal-i-chugun.html

How to weld steel to cast iron?

Today, welding cast iron parts with steel is a common procedure that is used in a wide variety of industries: metallurgical, mechanical engineering, machine tool building and others. Previously, cast iron was one of the main materials used to create metal structures. Products made of cast iron have many advantages, while being relatively inexpensive.

Technology of welding cast iron with steel using consumable electrodes

Before starting any type of welding work, you need to prepare the metals to be joined. Their surfaces in the joint area must be cleaned to a characteristic metallic shine.

Cast iron is a porous metal, so oily liquids can penetrate its body quite easily and deeply. Therefore, areas where greasy stains are found must be cleaned until they completely disappear.

The welding mode itself depends entirely on the selected equipment.

• Welding steel to cast iron with a unit no-load voltage of more than 54 V is possible only when using alternating current.
• When the no-load voltage of the unit is less than 54 V (for many models of welding equipment this is a standard value), welding work is performed with direct current having reverse polarity.

Cast iron and steel parts in both situations are heated to 600 degrees to prevent them from expanding during the welding process.

To weld cast iron and steel, when their structure contains alloyed additives or the samples being joined have a sufficiently large cross-section, the following points must be taken into account.

• The parts are not preheated.
• The connection of two different metals is carried out using small rollers up to 2.5 mm long.
• The second roller is formed after the first one has completely cooled.

The tightness of the seam joint depends precisely on the two extreme points. When using this welding technique, there is no need to talk about the tightness of the connection between steel and cast iron, since each subsequent bead is placed on the previous bead, which is completely cold. In this case, the resulting seam will be quite fragile.

Some technical points of the welding procedure

• For this option of joining different metals, the selection of welding parameters and materials is carried out based on the limitations of the weldability of cast iron. If there are no special strength requirements for the weld, only nickel filler materials are used.
• Welding processes with increased specific heat input and the formation of a significant weld pool are not recommended.
• A number of cast irons, which contain a large amount of carbon, are considered non-weldable due to their tendency to form cracks.
• Cast iron and steel structural elements can be welded together directly using a nickel filler material made specifically for joining cast irons. But if critical deformation of the material occurs and significant loads occur, this will not be enough. In such situations, before welding a steel element to a cast iron product, it is recommended to fuse a nickel filler material on the surface of the cast iron part.
• Welding cast iron with steel can be done without preheating the metal, but only if the part will subsequently operate at temperature conditions greater than 300 degrees. In this case, small-sized products being welded are subject to general heating; when connecting large parts, only the welding zone is heated.
• The coefficient of linear expansion of cast iron is quite low, and this metal is also characterized by low ductility. Therefore, the shrinkage stress that occurs in the connection must be reduced. To do this, immediately after completion of welding it is necessary to forge the seam.
• A high-quality connection result can be achieved if small cross-section electrodes are used for welding, and surfacing is performed with short beads (no more than 5 cm) in the transverse direction. For this purpose, it is necessary to tilt the welding arc onto the previous roller, but not in the direction of the base metal.

Practice shows that all technologies for joining steel and cast iron developed to date are quite effective, but only if the welding mode and consumables are selected correctly.

Source: https://electrod.biz/splav/steel/kak-privarit-stal-k-chugunu.html

Welding cast iron with steel

Cast iron and steel are very similar metals, the only thing that differentiates them is their carbon content. There is more of it in cast iron. And it is this chemical element that complicates the process of welding cast iron. But the most important thing is that the carbon in its composition can be small granules or large ones.

So the first option can still be welded, but the second is almost impossible. Even with a seemingly well-carried-out welding operation, the result will still be poor.

And when we talk about such a technological process as welding cast iron with steel, it is necessary to understand that similar metals are still dissimilar. And this is the whole difficulty.

Steel can be welded to cast iron by electric arc welding using various electrodes. For example, domestic brands TsCh-4, OZCH-2 or OZL-25. Completely different electrodes, so they are used if the welding seam will be processed in the future or not.

If welding is carried out with further processing, then the OZL-25 or OZCh-2 electrode is used, in another case TsCh-4. The first electrode forms a homogeneous type of metal with high permeability and heterogeneity in the weld seam.

The latter value makes it possible for the metal not to burst during processing, because it relieves the stress inside the weld.

Consumable electrode welding technology for steel and cast iron

As with all welding processes, the first step is to prepare the two metals. They must be cleaned to a metallic shine in the welding zone. Since cast iron is a porous metal, oils and fats easily penetrate deeply into its body. So, it is imperative to clean areas with oil stains until they are completely removed.

As for the welding mode of cast iron and steel, everything will depend on the welding equipment.

• If the no-load voltage of the welding machine does not exceed 54 volts, which is a standard value for many types of welding equipment, then the welding process is carried out by direct current of reverse polarity.
• If the open circuit voltage is above 54 volts, then alternating current is used for welding.

In both cases, it is necessary to heat both workpieces to a temperature of +600C. This is done with one sole purpose - to prevent large expansion of the workpieces in the welding zone. After all, there is also a reverse process.

That is, the greater the expansion, the greater the contraction when metals are cooled. This can lead to cracking of the weld. If you take into account all the above recommendations, the end result will be a high-quality seam.

Moreover, it can be obtained in just one pass with the electrode.

If the composition of steel and cast iron contains alloyed additives, or the workpieces themselves are thick-walled parts, then it will be necessary to cook cast iron with steel using a different technology.

• Firstly, no preheating is used.
• Secondly, two metals must be welded to each other using small beads no longer than 2.5 mm.
• Thirdly, the next roll is formed only after the previous one is well cooled.

It is the last two positions that will affect the tightness of the seam. That is, when welding steel and cast iron using this technology, there is no need to talk about the tightness of the seam. Because the subsequent roller is superimposed on the cooled previous one. In addition, the weld itself will have increased fragility.

Argon arc welding

In principle, what was said above fully applies to argon arc welding with a non-consumable electrode in a shielding gas environment. The only thing added to welding technology is additive and gas. Everything is clear with gas, because it is the same for all types of welding, regardless of the type and type of workpieces being joined, or rather, their metals.

But the filler material is selected according to the properties of the base metal being welded. And since there are two of them, you will have to take into account the welding abilities of each of the two. And since cast iron is, so to speak, weak, then the additive should be selected according to it. So, as a filler material, you can use welding flux-cored wire, from which the coating is beaten off. Some craftsmen use strips of cast iron, cut into small pieces.

True, both materials can be used only if the welder has enough experience in using this technology. The thing is that an incorrectly set mode and an incorrect melting speed of the additive can lead to the formation of so-called intermetallic structures in the weld pool. They have increased fragility. This is why practical experience is considered an important component of the quality of the final result when welding steel and cast iron with a non-consumable tungsten electrode.

Therefore, some purely practical advice.

• To weld two metals, it is best to use nickel-based additives, which were specifically invented for welding cast iron products. But if the requirements for the strength and reliability of the joint are quite large, then even such an additive will not be able to fulfill them.
• You cannot cook cast iron with steel with a wide bath and large heat inputs.
• It is recommended to deposit a nickel additive on the cast iron edge before starting welding work. That is, to form the so-called transition layer.
• You can weld cast iron to steel without preheating or with it. The first option is chosen only if during operation of the welded part it will not be subjected to great heat, no more than +300C. If there are no such requirements, then heating will have to be done. Small workpieces are heated completely, large ones only in the welding zone.
• Cast iron is a metal with low ductility and very low linear expansion compared to steel. Therefore, it is very important to reduce shrinkage stresses in the weld. Cast iron shrinks a little, steel, on the contrary, shrinks a lot.

What can you do about the last position? The greatest effect can be achieved by hitting the weld with a hammer. This process is called forging. For this, a hammer with a rounded head is used. The metal must be beaten to such an extent that a ringing sound is produced.

There is another option to increase the effect. To do this, you will have to weld with a large diameter filler wire. The seam itself must be done using rollers 4-5 cm long each. In this case, the electric arc should be directed towards the previous roller. It is necessary to cook evenly along the joint without oscillatory movements.

Electrodes

Electrodes have already been discussed above, but it is necessary to identify some serious positions on which the quality of the final result depends.

• TsCh-4 can be used for both cold and hot welding of cast iron and steel. They are also used to perform surfacing, soldering and repair of casting defects. In addition to steel and cast iron, this brand of electrode can also weld workpieces made of high-strength malleable cast iron. Cooking with such electrodes can only be done in the lower position using direct current of reverse polarity.
• OZCH-2 is used in exactly the same positions as the previous consumable. But experts recommend welding thin-walled workpieces with it. In addition to the lower position, the electrode also cooks well in the vertical position.

By the way, welding of two metals (cast iron and steel) is considered to be of higher quality when manual electric welding is used. But, as mentioned above, if the process is carried out with preheating. Cooling of welded steel and cast iron parts must be carried out slowly. Therefore, after completing the work, the welded structure must be covered with dense material. It’s better to put it in an oven, where the parts were heated before welding, and cool the assembled part along with it.

These are the technologies used today to connect steel and cast iron workpieces. As practice has shown, they all cope well with this, the main thing is to choose the right consumables and welding modes.

Source: https://svarkalegko.com/tehonology/kak-privarit-chugun-k-stali.html

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.

Preparation for welding

Preparatory operations must be carried out carefully and carefully, as this is one of the fundamental principles of obtaining a high-quality connection:

• the structure is cleaned of dirt, debris and dust;
• then you should degrease the parts with a solvent, for example, acetone;
• when working with thin cast iron, you need to use pads to remove heat ;
• edge cutting should be done before welding thick-walled products; for this, a file or grinder is used;
• cracks must be drilled along the edges and cut to their entire length; an alternative method is to cut out the cracks and round ;
• depending on the chosen welding method (hot or cold), the product is heated or not. heated using various equipment: ovens, gas burners, or using improvised means: a blowtorch.

Welding methods

Experts distinguish 3 methods of welding cast iron:

1. Hot is carried out by heating the cast iron parts before making the connection, the temperature is 600-650°C. This method cannot be used at home.
2. Semi-hot is practically no different from the previous method, the difference is only in the heating temperature, the product is heated to 300-350°C.
3. Cold implies the absence of heating of work products. Welding cast iron with an electrode at home is carried out using this technology.

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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.

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.

Security measures

Carrying out welding work at home requires careful and precise adherence to safety precautions. The most important points:

• the room in which welding work is carried out must be illuminated and ventilated ;
• It is mandatory to use means for grounding ;
• Cast iron does not respond well to rapid cooling, so its surface must be protected from moisture ;
• personal protective equipment when working .

Source: https://WeldElec.com/info/kak-pravilno-varit/chugun/v-domashnix-usloviyax/