Method for producing large-sized seamless pipeline tube

Abstract

The process of producing seamless steel pipe includes the following steps: heating the pipe blank to 1000-1200 deg.c in a rotating hearth furnace, bidirectional hot centering in a bidirectional hot centering set, piercing in a conic roll piercer with front rotating feeder and back rotating mandrel to obtain hollow billet, rolling in five sets of three-roller plug mill, extracting in a three-frame extracting mill, hot sawing to crop ends, passing through fast chain beam and walking beam, straightening in a multi-roll straightening machine, inspecting and packing. The present invention can produce seamless steel pipe product in different sizes, and has high production capacity, high product quality and other advantages.

Description

Technical field: [0001] This patent relates to a production method of a line pipe, especially a production method of a large seamless line pipe. technical background: [0002] For the production of large-diameter, thick-walled, and extra-thick-walled seamless steel pipes, the traditional methods are pipe jacking-extrusion method and Pilger method. The obvious disadvantages of the above two production methods are: 1. Low growth rate of tube blanks; 2. Low production capacity; 3. Poor quality of inner and outer surfaces of products, and inaccurate geometric dimensions. [0003] In the late 1960s, the Italians completed the MPM pipe rolling process (that is, the two-roll continuous pipe rolling process) and obtained a patent. This is the first process patent after the first continuous pipe rolling mill in the United States was put into production in 1890. Subsequently, by the beginning of this century, more than 20 sets of continuous rolling mills worldwide have been in produc...

AI Technical Summary

Problems solved by technology

The obvious disadvantages of the above two production methods are: 1. Low growth rate of tube blanks; 2. Low production capacity; 3. Poor quality of inner and outer surfaces of products, and inaccurate geometric dimensions

However, the specifications of the above-mentioned units are at best a maximum diameter of 480mm and a wall thickness of 60mm, which means that domestic Pilger units (including units under construction) and Wuhan 471 units are included in the scope of production of large-diameter, thick-walled, and extra-thick-walled units. The outer diameter and wall thickness of the steel pipe can only be 580mm and 80mm, and the rotary expansion unit can only produce steel pipes with a maximum of 1422mm