Select high-quality 304 and 316L stainless steel raw material billets that meet the standards and undergo hollowing, heading, annealing and other operations.
1. Production steps of
stainless steel seamless pipes:
1. Select high-quality 304 and 316L stainless steel raw material billets that meet the standards and undergo hollowing, heading, annealing and other operations.
2. After completing the above operations, it is followed by a multi-pass cold drawing (cold rolling) process. The cold rolling of the pipe is carried out on a multi-roll rolling mill, and the stainless steel pipe is rolled in a ring-shaped hole composed of a variable-section circular hole groove and a stationary conical head.
3. After cold rolling, the stainless steel pipe will have a large yield coefficient and is not suitable for expansion and bending. In order to meet the hygienic standards of stainless steel pipes, the cold-rolled pipes also need to undergo bright annealing, demagnetization, pickling, straightening and other steps.
5. During the pickling process of stainless steel pipes, the pipe fittings can remove oil stains, rust spots, welding spots, oxide layers, free iron and other dirt on the surface of the workpiece while pickling and passivating. The surface becomes uniform silver-white after treatment, while preventing metal from excessive corrosion and hydrogen embrittlement and inhibiting the generation of acid mist.
6. After the stainless steel pipe has gone through the above process, the next step is the polishing process. The standard number of polishing mesh for the inner and outer walls of the pipe is 400 mesh. The surface finish of the inner and outer surfaces of the polished pipe can reach the mirror standard (that is, the sanitary standard).
7. After polishing, the stainless steel pipe needs to be inspected by a metal flaw detector (or water pressure test) for internal flaw detection and strict manual selection by the steel pipe quality inspector. Only qualified products can be packaged and shipped.
2. The production process of stainless steel seamless pipes.
Production process: 1. Steelmaking → 2. Rolling round steel (peeling) → 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 detection → 10. Labeling and certificate of conformity → 11. Packaging → 12. Delivery
