(Rolled) seamless steel pipe: round tube → heating → perforation → Heading → annealing → pickling → oiled (copper) → multi-pass cold drawn (cold) → billet tube heat treatment → → straightening → hydrostatic test (testing) → mark → storage. Cold drawn (rolled) than hot-rolled seamless steel pipe rolling method (squeeze seamless steel pipe) complex. Their first three steps of the production process is basically the same. Differs from the beginning of the fourth step, after playing a round tube empty to begin with annealing. After annealing to use a special acidic pickling liquid. After pickling do stainless steel doors, oiled. Then followed through many times of cold drawn (cold) and then blank tube, special heat treatment. After the heat treatment, it will be straightened. 304 stainless steel has good cold and hot processing performance, can be common to a variety of hot and cold processing production forgings, rod, wire, sheet, strip and other metallurgical products of stainless steel wire frame, thermal processing temperature range of 900 -1180 ℃. Easier cold steel door material, no special difficulties, due to two kinds of cold-hardened steel is easy, when excessive cold deformation, the required intermediate annealing treatment, in order to facilitate further processing. The stainless steel doors, stainless steel doors, Shengda Po-commerce provided by the Tianjin Shengda Jie Bao Trading Company. Bao Jie Tianjin Shengda Trading Company (www.sdbjsm.com) strong, credible, in Tianjin's daily hardware industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Shengda treasure-commerce and you hand into the brilliant, for a better future!