①Main production process of hot-rolled seamless steel pipe (main inspection process):Tube billet preparation and inspection → tube billet heating → perforation → pipe rolling → steel pipe reheating → fixed (reduced) diameter → heat treatment △ → finished pipe straightening → finishing → inspection (

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