How are stainless steel pipes produced?

① Hot-rolled seamless stainless steel pipe
Hot-rolled seamless pipes can generally be divided into medium and low pressure boiler steel pipes, general steel pipes, Wuxi high pressure seamless stainless steel pipe wholesalers, high pressure boiler steel pipes, stainless steel pipes, alloy steel pipes, etc. Its production process is: check and prepare the tube billet, heat the tube billet, perforate, sub crown, heat the rough pipe, determine the diameter, heat treatment, straighten the finished tube, finish, inspect, and put into storage. The raw material of the seamless steel pipe is a round tube billet, which needs to be cut into a skin of about 1m in length by a cutting machine and sent to the furnace for heating by a conveyor belt. The high temperature is about 1250℃, and the fuel in the pyrolysis tube is mostly acetylene or radon. After the tube embryo is out of the furnace, it needs to be perforated, and then it is continuously rolled and three-rolled. Sizing is to use a conical drill bit to rotate the drill billet under high pressure to form a steel pipe.
② Cold-processed seamless stainless steel pipe
Usually cold rolling is the main method, supplemented by cold drawing. About 65% of seamless pipes require us to make a finished product through cold processing, which promotes the development of cold processing process production equipment. Generally, there are three types of cold processing technology: cold rolling process, cold drawing process and cold rolling and cold drawing composite process. Foreign countries mostly use cold drawing and cold rolling joint process to produce seamless steel pipes.
The process flow of cold processing and cold drawing to produce seamless stainless steel pipes is: purchasing pipe billets-cutting-heating-perforation-fixed length cutting-hammer-pickling-lubrication-drawing-annealing-head cutting-water pressure-inspection-finished products. Cold drawn seamless stainless steel pipes have the advantages of high production efficiency, convenient specification change, strong flexibility, simple equipment and production methods. However, there are also some defects, such as small pass variable, long production and processing time, high metal consumption, poor surface finish, etc.
The process flow of cold rolling to produce seamless stainless steel pipes is: steelmaking-round steel rolling-perforation-cold drawing-cold rolling-annealing-bright polished inner surface-polished outer surface-acceptance inspection-storage and packaging. Cold rolling process analysis can well improve the surface quality of seamless stainless steel pipes, and the production management efficiency is high. For example, Shanghai Tianyang uses raw materials from mainstream domestic steel mills, through cold drawing, heat treatment and pickling processes, and finally through 320 mesh surface polishing, with high surface finish and precise size, suitable for high-precision ferrule connection application pipeline system.
③Hot extrusion seamless stainless steel pipe
The hot extrusion process commonly used abroad is one of the hot processing production processes for seamless stainless steel pipes. Compared with rolling production enterprises, the extrusion method causes the metal to be subjected to three-way compressive stress during the deformation development process. Under the best process conditions, it not only improves the deformation resistance of the thermoplastic poor steel pipe, but also improves its internal and external surface quality, which is more suitable for the production of multi-specification, small batches of stainless steel pipes, such as oblique piercing machines that cannot be processed, such as high alloy pipes. Its process flow is: tube peeling, cutting, drilling, chamfering, cleaning the blank, heating, expanding the hole, heating, extrusion, straightening the steel pipe, shot peening, cutting the head and tail, pickling, inspection, packaging and storage.