What welding method is used for wrought iron castings will not break

You can try it with Erbao welding.

Cast iron process. Pros:

1.It can produce parts blanks or parts with complex shapes;

2.Castings have a wide range of applications and are not limited by size, shape and weight;

3.Casting production costs.

Lower; 4.The amount of cutting of castings is small, which can reduce machining costs.

Cons: 1The structure of the casting is not dense enough, there are defects such as shrinkage porosity, porosity, slag, cracks, etc., uneven grain thickness, and mechanical properties of the casting.

Lower, lower impact resistance;

2.There are many casting production processes, and the process control is cumbersome, which is easy to produce waste.

Welding process. Pros:

1.High speed, large depth, small deformation.

2.It can be welded at room temperature or under special conditions, and the welding equipment is simple. For example, lasers pass through electromagnetic fields.

The beam is not offset; Lasers can be welded in vacuum, air, and some gaseous environments, and can be welded through glass or materials that are transparent to the beam.

3.It can weld refractory materials such as titanium, quartz, etc., and can weld heterosexual materials with good results.

4.After laser focusing, the power density is high, and the aspect ratio can reach 5:1 and up to 10:1 when welding high-power devices.

5.Micro welding is possible. Laser beams.

After focusing, a small spot can be obtained, and it can be accurately positioned, which can be applied to the assembly welding of micro and small workpieces produced by mass automation.

Cons: 1The assembly accuracy of the weldment is required to be high, and the position of the beam on the workpiece must not be significantly offset.

This is because the laser focus is small and the weld is narrow, which is a filler metal material. If the assembly accuracy of the workpiece or the accuracy of the beam positioning does not meet the requirements, it is easy to cause welding defects.

2.The cost of lasers and their associated systems is high, and the one-time investment is large.

3.Laser welding.

is to take advantage of high energy density.

The laser beam is used as a heat source for an efficient precision welding method. It is one of the important aspects of the application of laser material processing technology. Generally, a continuous laser beam is used to complete the connection of materials, and the metallurgical and physical process is very similar to that of electron beam welding, that is, the energy conversion mechanism is completed through a "key-hole" structure.

The equilibrium temperature in the cavity reaches about 25,000 degrees, and the heat is transferred from the outer wall of the high-temperature cavity, causing the metal surrounding the cavity to melt. The small hole is filled with high-temperature steam generated by the continuous evaporation of the wall material under the irradiation of the light beam, the light beam continues to enter the small hole, and the material outside the small hole is flowing continuously, and the small hole is always in a stable state of flow as the beam moves. The molten metal fills the void left by the removal of the hole and condenses, and the weld is formed.

You can compare the advantages and disadvantages of the two processes, and then according to the specific material of the bed rail and the combination requirements of the link part, the right process is good.

The strongest way to weld cast iron:

1. Thermal welding method.

Preheat the casting to 600 700 before welding, keep the welding process above 400, and slowly cool it to room temperature after welding. The use of thermal welding method can effectively reduce the temperature difference of the welded joint, thereby reducing the stress, and at the same time, it can also improve the plasticity of the casting and prevent the appearance of white mouth structure and cracks.

2. Cold welding method.

For cold concealed liquid welding, the workpiece is not preheated before welding, or the preheating temperature does not exceed 300. Heterogeneous welds are also known as non-cast iron welds. Arc cold welding is the most commonly used method for cast iron welding.

Since the casting does not need to be preheated during the welding process, the welding process is greatly simplified, which not only reduces the welding cost, but also improves the working conditions of the welding personnel. In addition to this portability, it has the characteristics of wide adaptability, all-position welding and high welding efficiency, so arc cold welding is a very promising welding process.

3. Heating and sub-strain welding method.

The weldment is heated first, and the "heating and stress reduction zone" of the weldment is heated before and during welding so that it does not hinder the shrinkage of the weld, thereby reducing internal stress and avoiding cracks.

Yes, cast iron will be welded with two different welding processes.

It can be repaired by using the gas welding process of "copper welding rod + borax". It can also be welded directly with cast iron electrodes, but the weld needs to be polished after welding.

Cast Iron Welding Technical Requirements:

1. Welding rods can be selected according to the type of cast iron. If the conditions do not allow and use E5306, E5307 can also be welded, but the effect is not as good as the welding effect of cast iron electrode.

2. Dry the welding rod and heat the iron castings. Iron castings need to be heated to more than 800°C before they can be welded.

3. After welding, continue to heat the cast iron workpiece to more than 800°, cool it with the furnace, or bury it with quicklime, or wrap it with asbestos, so as to cool it slowly and achieve the purpose of reducing the internal stress of the casting.

There are several welding methods for cast iron cracking:

1. J506 or J507 steel electrode.

2. J422 winding copper welding wire.

3. Argon arc welding with steel welding wire.

4. Carbon dioxide protection welding.

5. Z-308 and other cast iron electrode welding.

6. Brazing with brazing wire.

There are many methods, but the success rate is very low, and many masters who often weld cast iron are also very troubled by the crack welding repair of cast iron. The 1st, 2nd, and 3rd methods are very hard and brittle after welding, easy to crack and cannot be machined.

Causes of cracking of castings:

1. The wall thickness of the casting is uneven, and the forming shrinkage at the junction of thin and thick walls and the turning point is blocked.

2. The temperature of the mold is low and the pouring temperature is low, resulting in poor filling, resulting in incomplete fusion of the metal matrix, insufficient strength after solidification, and easy to crack, especially the parts far away from the inner gate.

3. The mold retention time of the casting is too long, which makes the grain of the die casting coarse.

4. The impurity content of the casting alloy is too high, which reduces the plasticity of the alloy, especially the high content of iron or the low content of silicon.

5. Improper configuration of the push rod or uneven ejection force makes all parts of the die-casting rubber can not be demoulded at the same time, and in the process of demoulding, it will cause the demoulding tilt and crack the die-casting.

6. The strength of the molded parts is not enough, especially the slender core, which will be distorted and deformed when filling, which will hinder the smooth demoulding of the casting.

7. There are lateral pits on the surface of the molded parts along the demoulding direction, or because the demoulding slope of the molded parts is too small, the grinding of the surface is not sufficient, which causes the demoulding resistance to increase.

Large, die castings are torn under greater demoulding resistance. <>

The conventional method of preventing cracks adopts the welding process of heat welding, and the preheating before welding and the thermal insulation treatment after welding can effectively prevent the generation of cracks, and is also suitable for some welded workpieces that have the conditions to do preheating and thermal insulation and the iron castings whose repair value is not particularly high.

1. A general term for an alloy of cast iron mainly composed of iron, carbon and silicon. In these alloys, the amount of carbon is greater than what can be retained in the austenitic solid solution at eutectic temperature.

2. Iron-carbon alloy with a carbon content of more than 2%. Industrial cast iron generally has a carbon content of: Carbon is mostly found in graphite form in cast iron, and sometimes in cementite form.

In addition to carbon, cast iron also contains 1% 3% silicon, as well as elements such as manganese, phosphorus, and sulfur. Alloy cast iron also contains elements such as nickel, chromium, molybdenum, aluminum, copper, boron, vanadium, etc. Carbon and silicon are the main elements that affect the microstructure and properties of cast iron.

3. The heat treatment of gray cast iron can only change its matrix structure, but cannot change the morphology of graphite, therefore, heat treatment can not obviously change the mechanical properties of gray cast iron, and the low plasticity of gray cast iron makes it difficult to implement the heat treatment method of rapid cooling, so the heat treatment of gray cast iron is subject to certain limitations. Its heat treatment is mainly used to relieve stress and improve cutting performance.

4. Due to the uneven wall thickness of the casting, in the process of heating, cooling and phase transformation, there will be effective force and microstructure stress. In addition, large parts are also prone to residual stresses after machining, all of which must be eliminated. The usual heating temperature for stress relief annealing is 500 550 and the holding time is 2 8h, and then the furnace is cooled (gray iron) or air cooled (ductile iron).

This process can eliminate 90-95% of the internal stress of the casting, but the structure of the cast iron does not change. If the temperature exceeds 550 degrees or the holding time is too long, it will cause graphitization, which will reduce the strength and hardness of the casting.

How to not crack in cast iron mainly through the following points.

1. Rapid welding and heat preservation after preheating will effectively reduce the risk of cracks.

2. If there is no hot welding condition for on-site repair, you can use cast iron electrode welding suitable for cold welding and crack resistance, such as wewelding777 special cast iron electrode welding, which is often used for on-site important cast iron equipment repair, and the cold welding process saves the process trouble of hot welding.

3. Small current and small standard welding during cold welding.

The crack of cast iron welding is caused by the poor plasticity of the cast iron material, which is caused by the action of welding stress, and the main way to remove the crack is to control the stress concentration. The residual heat before welding can be carried out, and the parts that hinder the welding deformation can also be heated, and a relatively large line energy can be used during welding to ensure that the welding area has a higher temperature, and the insulation can be carried out to cool slowly.

Note: Before the welding and repair of cast iron, do not use the welding rod to try to weld without a good welding process, such welding will cause secondary cracks, and even scrap the workpiece, and more importantly, the subsequent cast iron welding may not be able to be carried out, and there is no room for recovery.

Welding process. Before welding, the cracks are polished, the cracks must be cleaned and welded with an angle grinder, no need to preheat the workpiece, for the connected cast iron welding, MG289 or MG210 can be used for direct welding, and you can also use better performance Magna cast iron electrode (including Magna 770 and Magna 777, referred to as M770 and M777 have no other names, beware of counterfeiting).

Machining, MG289 and MG210 cast iron electrodes, welding beads are also machined to process the specific cast iron welding process, which needs to be determined according to the use of the environment.

The conventional method of preventing cracks adopts the welding process of thermal welding, and does preheating before welding and thermal insulation treatment after welding, which is that the process is more troublesome, but can effectively prevent the generation of cracks, and is also suitable for some welded workpieces that have the conditions to do preheating and heat preservation and repair value is not particularly high iron castings.

If the conditions do not allow hot welding under the premise of using cold welding process welding as much as possible, at this time the requirements for the electrode itself will be relatively high, the need for welding electrode with good crack resistance, wewelding 777 special electrode is a good choice, the use of wewelding777 supporting the operation process specification to weld this kind of cast iron welding cracks can be avoided.

Hello, the warranty of weldments is generally with the warranty period of the whole project or all products, generally three months for weldments!

There are many reasons for cracks in welding, the strength of cast iron is low, the plasticity is relatively poor, and at the same time, the local uneven heating in the process of welding, resulting in greater welding stress, the weld and the heat-affected zone are prone to cracks, if you want not to crack, the fundamental solution is to eliminate the residual stress of welding, Huayun vibration aging overall stress relief effect can, if you eliminate the weld alone, it is recommended that Hawker can treat the stress of the weld, experience, thank you.

Secondary cracking can be avoided by using the non-welded metal seam repair process. And there is no stress, no deformation, no leakage. The strength and tightness are similar to that of the base metal.

Cast iron castings should be welded by cold welding process as an exception, and special cast iron electrodes suitable for cast iron and iron dissimilar welding should be selected, such as wewelding777, so that the tensile strength of 48 kg per square millimeter can be reached after welding, and good cracking performance. This is the requirement of the cold welding process of wewelding777 special cast iron electrode, and the small current and small specification prevent stress cracks caused by excessive temperature.

Iron castings have a high carbon content, so the weldability of cast iron is poor. Choose a special cast iron electrode (Z116 or Z308) for welding, the preheating temperature should reach 500, DC reverse connection, the welding current is controlled at 90 110A, and the welding bead is immediately hammered with a small hammer to prevent cracks from appearing.

You can use the heat welding method: preheat 600-700, weld with Z208 Z408 J422 J507, etc., keep the temperature not lower than 400 degrees during welding, and 650 degrees after welding to relieve stress, heat preservation and slow cooling.

Cold sweat: Z116 Z117 Z308, etc., welding process, short, dispersion, intermittent welding, hammer weld stress relief, welding out belongs to heterogeneous welds, no need to preheat before the process.