Warm machining method for making carbon steel pipe and alloy steel pipe

Abstract

A warm machining technology for manufacturing carbon steel pipe or alloy steel pipe includes such steps as conticasting hollow pipe blank, surface machining, preheating to a temp between ambient temp and recrystallizing temp. heating to a temp over the recrystallizing temp, high-speed rolling, and cooling. Its advantages are simple process, high utilization rate of material, low cost and high quality.

Description

technical field [0001] The invention belongs to the metal pipe rolling technology. It specifically relates to a method for processing and manufacturing carbon steel pipes and alloy steel pipes. Background technique [0002] The manufacturing methods of existing carbon steel pipes and alloy steel pipes mainly contain perforated tube billet rolling method and strip forming welding method. The first traditional manufacturing method is to cast carbon steel and alloy steel into a solid billet and cut it to length. After reheating, it is sent to a two-roll or three-roll piercer to be pierced into a blank tube, and then the tube billet is hot-rolled and cold-rolled. Rolled to get the finished pipe. This method is generally used at present, but there are many processes, high energy consumption, inability to produce super-long pipes, and high pipe manufacturing costs. The yield from the solid billet to the first hot rolling pass is only about 80%. The second strip forming welding...

AI Technical Summary

Problems solved by technology

Although people have done a lot of work and efforts on the treatment of weld seams, it has not been able to completely eliminate the defects and leaks caused by weld seams fundamentally.

Therefore, it is limited in some important applications such as medium and high pressure boiler tubes, medium and high pressure fluid delivery pipelines and heat exchangers.