With the continuous development of oil and gas pipelines to large diameters and high pressures, spiral submerged arc welded steel pipes also continue to develop to large diameters, large wall thicknesses and high steel grades. The double wire submerged arc welding process is playing more and more in

The rust of steel in the atmosphere is the corrosion phenomenon of iron ionization to form unprotected iron oxides (rust), while the rust of 304 stainless steel pipe is also a kind of corrosion phenomenon. The difference is in the atmosphere. The ionization of iron and chromium in stainless steel