If the stainless steel pipe is welded, the inner and outer surfaces of the stainless steel pipe turn black and yellow. Because the purity of the welding gas is not enough or the back is caused by high-temperature oxidation and other reasons 310s stainless steel pipe recommends using the following three methods to avoid such things from happening.

1）Improve the purity of argon gas: Increase the purity of argon gas when used in stainless steel pipe welding. From the perspective of the outer surface of the stainless steel pipe, the brightness of pure argon is brighter than that of ordinary argon welding

2）The argon gas on the back should be well protected. The important 310s stainless steel pipe needs to be protected on the back after welding. Otherwise, high-temperature oxidation will cause oxidation of the solder layer to penetrate through the back and produce defects. The weld on the back is polished like slag, so it can effectively prevent back oxidation after protection.

3）You can apply a back protector on the back, which can save the argon gas protection, just apply a thickness of about 1 mm, and then form a thin film on the back to form a protective layer when welding the front.

If it is found that the weld mark of 310s stainless steel pipe is black, it can be cleaned with pickling passivation paste, which is to use acid to corrode the black oxide layer on the surface, and then rinse it with clean water.