Integrated welding seam-free taper pipe

Abstract

The invention relates to an integrated welding seam-free taper pipe which is characterized in that: the taper of the pipe is 0 degree to 30 degrees; the length is 1.5 meters to 20 meters; the diameter Phi is 89mm to 2000mm, and the wall thickness is 0.5 to 60mm. The manufacturing of the integrated welding seam-free taper pipe comprises the following steps of: (1) adopting a steel pipe with the diameter corresponding to that of the integrated welding seam-free taper pipe as raw material for hot expanding; (2) pre-manufacturing one or a group of moulds being the same to the welding seam-free taper pipe; (3) carrying out heating in an inductance coil of a hot expanding machine; and (4) carrying out surface finishing. The pipe has the characteristics of reasonable design, simple structure and convenient installation and maintenance. By adopting the integrated welding seam-free taper pipe to manufacture a taper oxygen lance used for converter steelmaking, the problems of production delay caused by adhesive slag on the lance body of the lance, heavy physical labor to workers and adverse effect to production are avoided, the service life of the blow oxygen lance is improved, the energy consumption thereof is reduced and the safe production is ensured.

Description

technical field [0001] The invention relates to a tapered pipe that can be used to manufacture a tapered oxygen lance for converter steelmaking, a tapered pipe fitting used in nuclear power plants, water purification pipelines and engineering buildings, in particular to an integral non-welded tapered pipe. Background technique [0002] In the metallurgical industry, in order to avoid and improve the slag sticking condition of the oxygen lance of the steelmaking converter, the method of changing the structure of the oxygen lance and the composition of the steel slag is usually adopted. It has been proved by practice that changing the outer tube and the middle tube of the oxygen lance into a cone shape is Can effectively avoid sticky residue. Most domestic steel mills adopt this form of converter oxygen lance. Due to the limitation of technology and processing methods, the cone-shaped converter oxygen lance currently used is the cone segmented welding type. Although this form ...

AI Technical Summary

Problems solved by technology

Most domestic steel mills adopt this form of converter oxygen lance. Due to the limitation of technology and processing methods, the cone-shaped converter oxygen lance currently used is the cone segmented welding type. Although this form solves the problem of gun body sticking However, due to the segmental welding, there are multiple welds on the entire oxygen lance, resulting in a significant decrease in the strength and fatigue strength of the oxygen lance compared with the overall tube, especially the working environment of the oxygen lance is very harsh, and the outer tube of the oxygen lance works The temperature changes periodically between room temperature and 1500°C. As a result, the strength and fatigue strength of the weld seam are severely reduced, and the weld seam cracks quickly. Some steel factories have had furnace collapse accidents due to weld seam cracking. Practice has proved that weld seam cracking is the One of the main failure modes of the oxygen lance, so there are serious safety and production hidden dangers in the cone segmented welded converter oxygen lance

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