Description
Stainless steel seamless pipe is a kind of hollow section, no joints around the strip of steel. The thicker the wall thickness of the product, the more economical and practical it is, the thinner the wall thickness, its processing costs will rise substantially.
The process of the product determines its limited performance. Generally, the precision of seamless steel pipe is low: uneven wall thickness, low internal surface brightness, high measuring cost, and the internal surface and pitting and black spots are not easy to remove; Its detection and shaping must be handled offline. Therefore, it embodies its superiority in high pressure, high strength and mechanical structure materials
Manufacturing method
According to different production methods can be divided into hot rolled pipe, cold rolled pipe, cold drawn pipe, extrusion pipe, etc.
1.1. Hot rolled seamless stainless steel pipes are generally produced on automatic tube rolling units. The solid tube billet is inspected and cleared of surface defects, cut into the required length, centered on the perforated end face of the tube billet, and then sent to the heating furnace for heating, and perforated on the perforating machine. In the perforation at the same time constantly rotating and advancing, under the action of the roll and the head, the blank tube gradually formed inside the cavity, called the capillary tube. It is then sent to the automatic pipe mill for further rolling. Finally, the wall thickness of the whole machine is adjusted, and the sizing machine is calibrated to meet the specification requirements. It is an advanced method to produce hot rolled seamless steel pipe with continuous tube rolling unit.
1.2. If you want to obtain smaller size and better quality seamless pipes, you must use cold rolling, cold drawing or a combination of both methods. Cold rolling is usually carried out on a two-high mill, in which steel pipe is rolled in an annular pass consisting of a circular groove of variable section and a stationary conical head. Cold drawing is usually carried out in 0.5 ~ 100T single chain or double chain cold drawing machine.
1.3. The extrusion method is to place the heated billet in the closed extrusion cylinder, and the perforating rod and the extrusion rod move together, so that the extrusion part is extruded from the smaller die hole. This method can produce small diameter steel pipe.
This kind of steel pipe can be divided into stainless steel seamless steel pipe and stainless steel welded steel pipe (welded pipe) two categories, according to the manufacturing process can be different
For: hot rolling, extrusion, cold drawing and cold rolling these basic types, according to the section shape can be divided into round pipe and shaped pipe, widely used is the circular steel pipe, but there are also some square, rectangular, semicircular, hexagonal, equilateral triangle, octagonal shaped stainless steel pipe.
For the steel pipe under fluid pressure to carry out hydraulic test to check its pressure capacity and quality, under the specified pressure does not leak, wet or expansion to qualify, some steel pipe also according to the standard or demander requirements for flange test, flaring test, flattening test.
Seamless stainless steel pipe, also known as stainless steel seamless pipe, is made of steel ingot or solid tube billet perforated into wool tube, and then made of hot rolling, cold rolling or cold dialing. The specification of seamless steel pipe is expressed by the outer diameter * the thickness of the wall in millimeters
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