Production process and steps for making stainless steel seamless pipes
Production process: 1, steelmaking → 2, rolling round steel (skin) → 3, perforation (annealing) → 4, cold drawing → 5, cold rolling (annealing, demagnetization, pickling, cleaning) → 6, inner wall polishing ( 400 mesh) → 7, outer wall polishing (400 mesh) → 8, air pressure detection → 9, surface inspection → 10, stickers and certificates → 11, packaging → 12, factory
Stainless steel seamless pipe production steps:
1. Use 304, 316L stainless steel raw material blanks with high quality standards to be emptyed, headed, and annealed.
2, after the above operation is followed by a multi-pass cold drawing (cold rolling) process, the cold rolling of the pipe is carried out on a multi-roll mill, and the stainless steel pipe is composed of a variable-section circular hole groove and a fixed conical head. Rolling in the annular hole type.
3. After the cold rolling, the stainless steel tube will have a large yield coefficient, which is not suitable for flare and bending. In order to meet the sanitary standard of stainless steel pipe, the cold rolled pipe needs to be brightly annealed, demagnetized, pickled, and corrected. Just wait for the steps.
5, the pickling process of stainless steel pipe, the pipe can remove the oil stain, rust spot, welding spot, oxide layer, free iron and other dirt on the surface of the workpiece while pickling passivation. After treatment, the surface becomes uniform silver white, and at the same time prevent metal from appearing. Over-corrosion and hydrogen embrittlement, inhibiting the generation of acid mist.
6, after the above process of stainless steel pipe, the next is the polishing process, the inner wall and outer wall of the pipe are polished to 400 mesh, and the polished surface of the pipe can reach the mirror standard (that is, the sanitary standard).
7. After polishing, the stainless steel tube needs to be subjected to internal flaw detection by a metal flaw detector (or water pressure test) and strict manual selection by the steel quality inspector. The qualified product can be packaged at the factory.
Note: Stainless steel seamless steel tubes are divided into cold-rolled tubes and hot-rolled tubes. For stainless steel sanitary tubes with high dimensional requirements and quality requirements, cold rolling, cold drawing or a combination of the two must be adopted.