Manufacturing method of L80-13Cr oil pipes

Abstract

The invention discloses a manufacturing method of L80-13Cr oil pipes. The manufacturing method comprises the steps of pipe blank heating, steel pipe penetration, tandem rolling of steel pipes, reheating of the steel pipes, tension reduction of the steel pipes, air hardening, tempering heat treatment, straightening of the pipes, cutting of heads and tails of the pipes and segmenting of the pipes. In the step of reheating the steel pipes, the heating temperature of the steel pipes is 960-1000 DEG C; in the step of tension reduction of the steel pipes, the temperature of the steel pipes after tension reduction is higher than 850 DEG C; and in the step of tempering heat treatment, the tempering temperature is 760-800 DEG C. Due to the adoption of the manufacturing method of the L80-13Cr oil pipes, the production cost of the products is obviously reduced while the productivity is substantially increased; and the mechanical property of the L80-13Cr oil pipes manufactured by the method can meet the API SPEC 5CT standard; and the impact toughness of the L80-13Cr oil pipes can be equal to and even substantially higher than that of the pipes subjected to common oil quenching or air quenching and tempering treatment.

Description

technical field [0001] The invention relates to a method for manufacturing oil pipes, in particular to a method for manufacturing L80-13Cr oil pipes. Background technique [0002] L80-13Cr tubing is a product specified in the API SPEC 5CT standard of the American Petroleum Institute. Its composition weight percentage is shown in Table 1, and its mechanical performance requirements are shown in Table 2. Due to the high alloy content of L80-13Cr tubing, it is the most difficult product to produce in the API SPEC 5CT standard. [0003] Table 1. (The balance is Fe and other unavoidable impurities except S and P, wt%) [0004] C Si mn P S Cr Ni Cu 0.15～0.22 ≤1.00 0.25～1.00 ≤0.020 ≤0.010 12.0～14.0 ≤0.50 ≤0.25 [0005] Table 2. [0006] [0007] The general manufacturing process of L80-13Cr tubing is as follows: [0008] Tube blank - tube blank heating - hot rolled steel pi...

AI Technical Summary

Problems solved by technology

[0010] (1) The pipe will crack during straightening;

[0011] (2) It is difficult to cut the head and tail of the pipe and segment it, so that the production cannot be carried out normally;

In addition, since hot rolling and direct tempering after rolling are not as stable as ordinary oil quenching or air quenching quenching and tempering, the impact toughness of products produced by these technical solutions may be lower than that of quenched and tempered pipes

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