Processing Technology of Hot-rolled Stainless Steel Seamless Tube

In the huge system of modern industry, hot-rolled stainless steel seamless pipes are like a solid backbone, supporting the stable operation of many key areas. From pipeline transportation in petrochemicals to the construction of electric power facilities, to precision manufacturing in aerospace, hot-rolled stainless steel seamless pipes have become an indispensable basic material with their excellent performance, playing a mainstay role in the industrial field.

Hot-rolled stainless steel seamless pipe processing technology, according to different production methods can be divided into hot-rolled tube, cold-rolled tube, cold drawn tube, extrusion pipe.

1. Hot-rolled stainless steel seamless pipe is generally produced in the automatic rolling mill unit. The solid tube is inspected and cleared of surface defects, cut into the desired length, centered on the end face of the perforation of the tube, and then sent to the heating furnace for perforation. In the perforation at the same time continue to rotate and forward, in the roll and the role of the head, the tube gradually formed inside the cavity, said capillary. And then sent to the automatic rolling mill to continue rolling. Finally, the whole machine is the whole wall thickness, the sizing machine to achieve the specifications. The use of continuous rolling mill production of hot-rolled seamless steel pipe is a more advanced method.

2. If you want to get smaller and better quality seamless tube, must be cold-rolled, cold drawn or a combination of the two methods. Cold rolling is usually carried out on a two-roll mill where the steel pipe is rolled in a ring-shaped bore formed by a variable cross-section round hole and a stationary tapered head. The cold drawing is usually carried out on a single chain or double chain type cold drawn machine of 0.5 to 100T.

3. The extrusion method is about to heat a good tube placed in a closed extrusion cylinder, perforated rods and squeeze bar with the movement, so that extrusion from the smaller die hole extrusion. This method can produce smaller diameter steel pipe.

This type of steel pipe can be divided into stainless steel seamless pipe and stainless steel welded pipe (with pipe) two categories, according to the different manufacturing processes can be: hot rolling, extrusion, cold drawing and cold rolling these basic types, Shape can be divided into tube and shaped tube, widely used is a round steel pipe, but there are some square, rectangular, semi-circular, hexagonal, equilateral triangle, octagonal and other profiled stainless steel pipe.

Unique advantages of hot rolling process

The hot rolling process gives stainless steel seamless pipes many unique advantages, enabling them to perform well in many industrial scenarios.

In terms of size control, hot rolling can achieve large deformation at high temperature, making the size and shape control of the product more precise and the product quality more stable. It can meet the production needs of large-size and thick-walled pipes. The outer diameter of the seamless pipe produced is generally greater than 32mm and the wall thickness is 2.5-75mm, which is difficult to achieve with many other processes.

 

In terms of performance optimization, the high-temperature rolling process can refine the grain size of stainless steel materials, destroy the casting structure of the steel ingot, remove microstructural defects, make the steel structure denser, improve its mechanical properties, and enhance the strength, toughness and corrosion resistance of the product. In some chemical and petroleum transportation scenarios that have high requirements for pipeline strength and corrosion resistance, hot-rolled stainless steel seamless pipes can serve stably.

 

In terms of production efficiency, although hot rolling may be slightly inferior to continuous rolling and other processes in terms of output per unit time, compared with some complex cold processing processes, it can be produced continuously and does not require frequent intermediate annealing and other treatments like cold rolling. The overall production efficiency is higher and can meet the needs of large-scale industrial production.

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