Manufacturing method of super austenitic stainless steel seamless steel pipe with large diameter

Abstract

The invention discloses a manufacturing method of a super austenitic stainless steel seamless steel pipe with the large diameter, and relates to the technical field of production of seamless steel pipes with the large diameters. The manufacturing method comprises the steps that first a super austenitic stainless steel hollow ingot cylindrical tube blank is prepared by adopting an electroslag remelting technology, then surface treatment of an inner circle and an outer circle, heating, diameter enlarging and perforation and skew rolling are conducted, then intermediate heat treatment, cold rolling, intermediate heat treatment and cold rolling again, and heat treatment of a finished product are conducted, and finally, finishing is conducted. According to the manufacturing method of the superaustenitic stainless steel seamless steel pipe with the large diameter, the electroslag remelting technology is utilized to manufacture the hollow blank, and intermediate casting, forging and mechanical punching processes are reduced; and the perforation difficult problem that the center of the blank cannot form the Mannesmann effect during perforation of super austenitic stainless steel is solvedby using the hollow blank for perforation, the yield is high, the finished steel rate is more than 85%, the production cost is reduced, and the production efficiency is high.

Description

technical field [0001] The invention relates to the technical field of production of large-diameter seamless steel pipes. Background technique [0002] The traditional manufacturing method of the existing super austenitic stainless steel seamless steel pipe is: use the electric furnace smelting technology to cast a solid billet, forge the casting billet into a solid forging billet cylinder, and use the forged billet cylinder as the pipe billet, and the solid pipe billet Use a mechanical drilling machine to open the core hole, heat the hollow tube blank, use the inner and outer molds to press, ream and elongate the hole in a hot state, use the inner and outer molds of different diameters for reaming and elongation, and then use the lathe to bore the inner hole and turn the outer circle method to produce seamless steel pipes. [0003] The traditional manufacturing method of traditional super austenitic stainless steel has the following defects: [0004] 1. The metal yield of...

AI Technical Summary

Problems solved by technology

[0004] 1. The metal yield of the product is low, and the finished product rate is 40%;

[0005] 2. The production cost is high, and the hole needs to be heated and reamed many times, the fuel consumption is large, and the tooling cost is high;

[0006] 3. Low production efficiency and long production cycle;

[0007] 4. The diameter of the product is small, the length is short, and the length is about 4000mm. Adding welded joints in the long-distance pipeline connection has potential safety hazards