Cold-drawing and cold-rolling mixed molding method of stainless steel seamless pipe

Abstract

The invention discloses a cold-drawing and cold-rolling mixed molding method of a stainless steel seamless pipe. The method comprises the following steps: preparing a pierced billet; cutting off the head and the tail of the pierced billet; pickling a pierced billet blank for the first time; coping, cold rolling and unoiling the pickled blank; judging whether the requirements of the finished product are met or not; if so, carrying out annealing treatment; lubricating and cold-drawing a welding head (drive head) of the annealed steel pipe semi-finished product; carrying out solid solution heat treatment on the finished product; straightening, fixing and chopping the finished product; pickling the finished product; carrying out finished product inspection, wherein the finished product inspection comprises the steps: surface inspection, water pressure detection, eddy current inspection, ultrasonic flaw detection, intergranular corrosion testing, grain size testing, tension test, expansion test, flattening test, hardness test, and carbon and sulfur analysis. The stainless steel seamless pipe manufactured by the method is accurate in size, small in ovality and good in quality.

Description

Technical field [0001] The invention relates to the technical field of seamless steel pipes, in particular to a cold-drawn and cold-rolled stainless steel seamless steel pipe processing method. Background technique [0002] At present, most of the stainless steel seamless steel pipe companies use cold drawn or cold-rolled processes to manufacture seamless steel pipes, and the seamless steel pipes manufactured by cold-drawn processes are not accurate due to the low precision of cold-drawn seamless steel pipes in China. , The ellipticity is large, the unevenness of the wall thickness is serious, and it does not meet the national standard requirements; the seamless steel pipe manufactured by the cold rolling process, the cold rolling mill mold is accurate, and the cold rolled seamless steel pipe has accurate dimensions, but in the cold rolling process Among them, due to the large amount of wall reduction and diameter reduction, fewer cold rolling passes, fewer heat treatment times, ...

AI Technical Summary

Problems solved by technology

[0002] At present, most stainless steel seamless steel pipe enterprises use cold drawing or cold rolling process to manufacture seamless steel pipes. For seamless steel pipes manufactured by cold drawing process, due to the low precision of domestic cold drawing machines, the dimensional accuracy of cold drawn seamless steel pipes is not accurate. , large ellipticity, serious uneven wall thickness, etc., which cannot meet the requirements of the national standard; the seamless steel pipe manufactured by the cold rolling process has precise molds of the cold rolling mill, and the size of the seamless steel pipe produced by cold rolling is accurate, but in the cold rolling process Among them, due to the large amount of wall reduction and diameter reduction, less cold rolling passes, less heat treatment times, and more residual application force, the grain size often fails to meet the requirements after heat treatment.

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