Welding of SS400 steel

In the SS400 steel welding process, the original austenite grains around the weld grow abnormally by the thermal cycle, leading to poor weld quality. However, it will definitely be different according to the differences in sweating heat input, weld penetration depth, fusion width and heat-affected area size. The heat-affected zone width has a significant impact on the post-weld performance of SS400 steel.

The width of the heat-affected zone is too large and will have a hardened structure of the solder joint, so that the strength and hardness of SS400 steel are much higher, and the plasticity and toughness are significantly reduced. At the same time, there is a welding point at the softening zone , and the mechanical properties at the welding point are extremely uneven.

At present, the method of improving the microstructure performance of joints mainly adopts post-weld heat treatment, but this method requires special installation and power consumption with time-consuming.