Whether the welding manipulator welding needs heat treatment

Welding manipulator post-weld heat treatment: Whether the welded structure of these two types of steel requires heat treatment depends on the strength level of one of the steels. For ordinary low alloy steels with a strength level greater than 50 kg and with a delayed cracking tendency, welding is required After that, the tempering heat treatment is carried out in time. The main function of tempering heat treatment is to create favorable conditions for hydrogen diffusion and escape, improve the microstructure near the seam area and eliminate welding residual stress, so as to prevent delayed cracks.

The tempering heat treatment temperature is generally controlled at a temperature below the Ac: line (that is, the temperature line at which austenite transforms into pearlite). For ordinary low-alloy steels containing vanadium, especially vanadium and platinum, heat preservation at about 600°C will significantly reduce the impact toughness value and increase the strength. The reason for this is generally believed to be caused by the precipitation of secondary carbides of vanadium at about 600°C. Therefore, the post-weld heat treatment of this type of steel should avoid this temperature range. The holding time is calculated as 4-5 minutes per millimeter thickness (but not less than 1 hour), and then air cooling or furnace cooling.

The temperature in the furnace for heat treatment should be uniform and consistent, and the specified heating rate, heating temperature, holding time and cooling rate should be observed during operation. Otherwise, if the furnace temperature or operation is improper, it will not only fail to achieve the intended purpose, but may produce the opposite result, which is more important for welded joints of steel with a strength level of more than 50 kg.