Warm machining method for making stainless steel pipe

Abstract

The invention discloses a method for manufacturing a stainless steel pipe by warm processing, which belongs to the metal pipe rolling technology. It is carried out in sequence according to the following steps, the surface of the tube blank is machined; the tube blank is preheated to between 400 ℃ and the recrystallization temperature; Rolling at high deformation rates in the range of 280 to 500 rpm; cooling of the rolled stock. The invention overcomes the disadvantages of the prior art, such as many processes, low yield, high manufacturing cost and unstable quality of finished products. The elongation coefficient of the invention is between 10 and 16, the rolling speed is between 10 and 20m / min, the tensile strength and elongation of the pipe are respectively 450MPa to 550MPa and 30% to 40%; the length of the pipe can reach more than 180m ; The overall rate from the tube blank to the finished product is about 80%, which is an advanced method of manufacturing stainless steel tubes by warm processing.

Description

technical field [0001] The invention belongs to the metal pipe rolling technology. Specifically relates to a method for processing and manufacturing stainless steel pipes. Background technique [0002] The existing manufacturing methods of stainless steel pipes mainly contain two kinds of perforated tube billet rolling method and stainless steel strip forming welding method. These two traditional processing methods, the former is to send the solid stainless steel billet to a 2-roll or 3-roll piercer after being cut to length and reheated to be pierced into a blank tube, and then the blank tube (tube billet) is passed through hot rolling or Cold rolling, processing and manufacturing into finished pipes. Said this manufacturing method is generally used at present. However, this processing method has many processes, high energy consumption, low yield (only about 60%), inability to process and manufacture ultra-long pipes, and high pipe manufacturing costs, and lacks market c...

AI Technical Summary

Problems solved by technology

However, since this processing and manufacturing method produces seam welded pipes, the quality of its weld seams has become the most concerned issue in use.

Although people have done a lot of work and efforts on the treatment of weld seams, they have not been able to fundamentally eliminate the defects and leakage caused by weld seams. Tubes for heat exchangers are restricted

Moreover, the processing methods in the prior art have not treated the surface of the billet, and the casting defects existing on the surface of the billet will inevitably be kneaded into the structure of the finished pipe in the subsequent rolling process At the same time, its heating and rolling are exposed to the air, and the iron oxide scale produced is also inevitably rolled into the structure of the pipe, which has a destructive effect on the quality of the finished pipe.

Looking at the existing methods for processing and manufacturing stainless steel pipes, there are many processes, high energy consumption, and high costs.