Article
Although almost all steel and non-ferrous metals canflash butt welding, but now most of them only flash butt weld iron pipes, steel pipes, flat iron flanges, large-section steel bars, etc. Due to the high price, resistance butt welding is used for other materials. If flash butt welding wants to weld high-quality joints, it must be welded according to the physical and chemical properties of the metal.
(1) Electrical and thermal conductivity For metals with good electrical and thermal conductivity, we use high current for short time and fast flash to weld. (2)High temperature strength For metals with high temperature and strength, we use increased plastic zone and increased upsetting force for welding. (3) Crystallization temperature range The wider the crystallization temperature range, the wider the semi-melted zone. We use larger upsetting pressure and upsetting allowance to squeeze out all the molten metal in the semi-melted zone to avoid defects such as shrinkage cavities, looseness and cracks caused by remaining in the joint. (4) Thermal sensitivity 1. For example, quenched steel, after welding, the joint will easily produce quenching structure, which will increase the hardness and reduce the plasticity. In severe cases, quenching cracks will occur. We generally use long-term preheating flash butt welding, and adopt measures such as slow cooling and tempering after welding. 2. For example, for austenitic stainless steel, the joints and heat-affected zones soften during welding, reducing the strength of the joints. We generally use faster flash speed and larger upsetting pressure to minimize the softening area and reduce the degree of softening. (5) Oxidizing property Oxide inclusions in joints have serious harm to joint quality. Therefore, preventing and eliminating oxidation is the key to improving joint quality. The composition of metals is different, and the generation of their oxidation properties is also different. If the melting point of the generated oxide is lower than that of the metal to be welded, the oxide will have better fluidity and will be easily expelled during upsetting. If the melting point of the generated oxides is higher than that of the metal to be welded, such as Si02, Al203, Cr203, etc., they must be discharged when the metal to be welded is still in a molten state. Therefore, when welding alloy steel containing more silicon, aluminum, chromium, and other elements, strict process measures should be taken to completely eliminate Remove oxides.
Wuxi Xinxing Welding Equipment Factory has been engaged in resistance welding machines for 29 years. Its core technology products include:Semi-automatic butt welding machine, Pneumatic-flash butt welding machine, multi-strand wire welding machine, foot pedal spot welding machine, pneumatic spot welding machine, medium frequency spot welding machine, row welding machine mesh welding machine, resistance automatic welding machine, energy storage welding machine, copper rod and aluminum rod disc circular welding machine, auto parts spot welding machine, sheet metal spot welding machine, home appliance hardware spot welding machine, small appliance spot welding machine, copper row copper pipe welding machine, nut spot welding machine, There are more than 300 types of stainless steel welding machines, foil strip spot welding machines, aluminum spot welding machines, multi-head spot welding machines, bag cage spot welding machines, mesh welding machines, ton rack welding production lines, resistance automatic welding machines, brazing machines, diffusion welding machines, projection welding machines, seam welding machines, wire and cable optical cable supporting equipment, etc. If you are interested in our welding equipment, please contact us.