Stainless steel cold-drawn steel pipe is a kind of hollow long round steel, mainly widely used in petroleum, chemical, medical, food, light industry, mechanical instrument lamp industrial transmission pipeline and mechanical parts.In addition, in the same bending, torsional strength, light weight, so also widely used in the manufacture of mechanical parts and engineering structures, also often used in furniture and kitchen utensils.
Production technology of stainless steel seamless tube a. round steel preparation;B. heating;C. Hot rolled perforation;D. cutting head;E. pickling.F. grinding;G. lubrication;H. Cold rolling;I. degreasing;J. Solution heat treatment;K. straightening;L. in cutting;M. pickling.Inspection of finished products.
Annealed stainless steel pipe with inner diameter of 6.0mm or above and wall thickness of 13mm or below can be tested by w-b75 wechsler durometer.Stainless steel tube with inner diameter greater than 30mm and wall thickness greater than 1.2mm shall be tested by rockwell hardness tester for HRB and HRC hardness.For stainless steel tubes with inner diameter greater than 30mm and wall thickness less than 1.2mm, use surface rockwell hardness tester to test HRT or HRN hardness.For stainless steel tubes with inner diameter less than 0mm and greater than 4.8mm, special rockwell hardness tester is adopted to test HR15T hardness. When the inner diameter of stainless steel tube is greater than 26mm, rockwell or surface rockwell hardness tester can also be used to test the hardness of inner wall of the tube.
Stainless steel seamless tube manufacturing method:
According to different production methods can be divided into hot - rolled tube, cold - rolled tube, cold - drawn tube, extrusion tube and so on.
1. The hot-rolled stainless steel seamless pipe is generally produced on the automatic tube rolling unit. After the solid tube blank is inspected and the surface defects are removed, it is cut to the required length, centered on the end face of the piercing end of the tube blank, then sent to the heating furnace for heating, and perforated on the piercing machine. Under the action of the roller and the plug, a cavity is formed in the blank, which is called the blank. Then send it to the automatic tube rolling machine to continue rolling. After that, the wall thickness of the whole machine is uniform, and the diameter is determined by the sizing machine to meet the specification requirements. Continuous rolling
It is an advanced method to produce hot-rolled seamless steel tube by tube mill.
2. In order to obtain seamless tube with smaller size and better quality, cold rolling, cold drawing or the combination of the two methods must be used. Cold rolling is usually carried out on a two high mill, and steel pipes are rolled in a circular pass composed of a variable cross-section circular groove and a fixed conical head. Cold drawing is usually carried out on single chain or double chain cold drawing machines of 0.5-100t.
3. Extrusion method is that the heated tube blank is placed in the closed extrusion cylinder, and the punch rod and the extrusion rod move together to extrude the extrusion part from the small die hole. This method can produce steel pipe with smaller diameter.
This kind of steel pipe can be divided into stainless steel seamless steel pipe and stainless steel welded steel pipe (seamed pipe). According to the different manufacturing process, it can be divided into hot rolling, extrusion, cold drawing and cold rolling. According to the section shape, it can be divided into circular pipe and special-shaped pipe. Circular steel pipe is widely used, but there are also some square, rectangular, semicircle, hexagon, equilateral triangle Octagonal and other special-shaped stainless steel pipes:
Hydraulic pressure test shall be carried out for steel pipes bearing fluid pressure to check their pressure resistance and quality. It is qualified if there is no leakage, wetting or expansion under the specified pressure. Some steel pipes shall be subject to crimping test, expanding test and flattening test according to the standards or the requirements of the demander:
Seamless stainless steel pipe, also known as stainless steel seamless pipe, is made of steel ingot or solid tube blank through perforation, and then by hot rolling, cold rolling or cold drawing. Specification of seamless steel pipe is indicated by outer diameter * wall thickness mm.