A kind of production method of hot simmering bent pipe

Abstract

The invention discloses a production method of hot-simmered bent pipes, which comprises: controlling the grade of B-type non-metallic inclusions in the steel of hot-simmered bent pipes to be ≤1.0 in the smelting process section; controlling the steel plate of hot-simmered bent pipes in the hot-rolling process section The termination temperature of water cooling after rolling is 470℃~520℃; in the hot rolling process section, the cooling temperature of steel plate stacking for hot-simmering and bending pipes is controlled to be 400℃~480℃, and the stacking cooling time is ≥24 hours; The cooling rate of the weld seam after welding of the bent pipe is ≤0.6°C / s; the diameter expansion rate of the hot bent pipe is controlled to be 0.72% to 0.78% in the pipe making process section. The above method effectively reduces the inclusions and internal stress in the weld area, solves the problem of weld cracking or weld inspection failure during the high-temperature simmering bending forming and heat treatment process of the hot-simmering pipe, and improves the quality of the hot-simmering pipe. Safety and reliability during oil and gas transportation service.

Description

technical field [0001] The present application relates to the technical field of production and manufacture of oil and gas transportation pipelines, in particular to a production method of hot-simmered bent pipes. Background technique [0002] In the field of oil and gas transportation, the pipelines used usually include hot-simmered elbows and conventional straight pipes. Hot-simmered elbows are mainly used for turning connections of pipelines in special terrains. strict. The manufacturing process of hot-simmered bent pipe is complicated. In the process of making steel pipes from steel plates, high-temperature simmered bending forming and tempering heat treatment are required. The conventional straight pipe will not crack in the weld area during the pipe making process. It can be seen that the weld seam of the hot-simmered elbow is the weakest link of the entire oil and gas pipeline, and there is an urgent need for a production method of the hot-simmered elbow, which can ...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a production method of hot-simmered bent pipes to solve or partially solve the technical problem that weld seam cracking defects often occur when hot-simmered bent pipes are bent and formed at high temperature

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