With the continuous development of economic construction in our country, the demand for stainless steel pipe, especially seamless stainless steel pipe (seamless pipe) is increasing, with good prospects for development. Because of its corrosion resistance, strength and toughness and good formability, seamless tube has a wide range of application value in the industry of daily use, light industry, heavy industry and building decoration. The market is more common round steel pipe, there are also some equilateral triangle, square, rectangular seamless stainless steel pipe.

① Hot rolled seamless stainless steel pipe

Hot rolled seamless pipe can be divided into medium and low pressure boiler steel pipe, general steel pipe, high pressure boiler steel pipe, stainless steel pipe, alloy steel pipe and so on. The production process is as follows: check and prepare the tube billet – heating the tube billet – perforation – subcrown – heating the waste tube – determining the diameter – heat treatment – straightening the finished tube – finishing – inspection – warehousing. The raw material of seamless steel tube is round tube billet, which needs to be cut by cutting machine to grow about 1m leather material, which is sent to the furnace for heating through the transmission belt. The high temperature is about 1250℃. Most of the fuel in the antipyretic tube is acetylene or radon. After the tube embryo comes out, it needs to be perforated, and then it is even tied and rolled by three rolls. The sizing method uses a conical drill bit to rotate the billet at high pressure to form a steel pipe.

Cold working seamless stainless steel pipe

Usually cold rolling, cold drawing as a supplement. About 65% of seamless tubes need to be made into finished products by cold processing, which promotes the development of cold processing equipment. General cold processing technology has cold rolling process, cold drawing process and cold rolling cold drawing combined process of three. Cold – drawing and cold – rolling process is used to produce seamless tubes abroad.

The process of cold drawing production of seamless stainless steel pipe is as follows: outer tube billet – cutting – heating – perforation – length truncation – hammer – pickling – lubrication – drawing – annealing – cutting head – water pressure – inspection – finished product. The cold-drawn seamless stainless steel pipe has the advantages of high production efficiency, convenient specification change, strong flexibility, simple equipment and production method. However, it has some defects, such as small pass variable, long production and processing time, more metal consumption and poor surface finish.

The process flow of cold working and cold rolling production of seamless stainless steel pipe is as follows: steelmaking – round steel rolling – perforation – cold drawing – cold rolling – annealing and shining – polishing inner surface – polishing outer surface – acceptance inspection – warehousing and packaging. The cold rolling process can improve the seamless stainless steel tube

Surface quality, high production efficiency. Like Shanghai Tianyang adopts domestic mainstream steel raw materials, through cold drawing and finishing rolling, heat treatment pickling process, and finally after 320 mesh surface polishing, with high surface finish, precision size and other characteristics, suitable for high precision card sleeve connection application piping system.

③ Hot extruded seamless stainless steel tube

Hot extrusion technology is one of the hot processing technology of seamless stainless steel pipe. Compared with the rolling production, the extrusion process causes the metal to be subjected to three compressive stresses during deformation. In THE BEST CONDITION, IT NOT ONLY IMPROVES THE deformation RESISTANCE, but also improves the inner AND outer surface quality of the steel pipe with poor thermoplasticity. It is more suitable for the production of multi-specification and small-batch seamless stainless steel pipe, such as high-alloy pipe which can not be processed by the diagonal rolling punch. Its technological process is: tube billet peeling – cutting – drilling – chamfering – cleaning blank – heating – reaming – heating – extrusion – straightening steel pipe – shot peening – cutting head and tail – pickling – inspection – packaging storage.

With the development of high speed and automation, thermal processing has become a better seamless stainless steel pipe processing technology, with high economic applicability, especially for the production process of steel pipe is difficult to deformation, but also plays a role in promoting.

Gradually speed up the process of industrialization in our country today, has a higher demand for seamless stainless steel pipe, only to improve the stainless steel smelting technology, according to the enterprise production scale and money into comprehensive consideration, choose suitable seamless stainless steel tube production process, to ensure the quality of seamless steel tube production, improve enterprise economic benefits.