Stainless steel square pipe is a hollow long strip of steel, because the cross-section is square, so it is called square pipe. It is widely used as a pipeline for transporting fluids, such as oil, natural gas, water, gas, steam, etc., and is also widely used in the manufacture of mechanical parts and engineering structures because it is lighter in weight when it has the same bending and torsional strength [1]. With the continuous development of modern industry, various metal materials have been widely used in construction, furniture, automobiles, electronics and other fields. In this process, stainless steel square pipe, as a high-quality metal material, has gradually been favored by people