If it is stainless steel water pipe welding, stainless steel water pipe inside and outside the surface of black, yellow this is because the purity of welding gas is not enough or on the back because of high temperature oxidation and other reasons, use the following three methods can avoid the occurrence of stainless steel water pipe black.

       Firstly, the purity of argon gas used in stainless steel pipe welding is improved to pure argon, which is brighter than that welded by ordinary argon when viewed from the surface of stainless steel pipe. Then the argon gas on the back should be well protected, and the important stainless steel water pipe should be protected on the back after welding, otherwise, high temperature oxidation will lead to the oxidation and defects of the welding layer through the back, and the welding surface on the back is polished like slag, so the oxidation on the back can be effectively prevented after protection. Finally, you can do the smear on the back of the back protective agent, is a kind of argon can save protection, smear about 1 mm thickness can be, and then in the front of the welding, on the back to form a thin film to form a protective layer.