A kind of seamless steel pipe heat treatment process

A technology of seamless steel pipe and process, which is applied in the field of seamless steel pipe manufacturing, can solve problems such as large differences in mechanical properties of the whole pipe, difficulty in meeting user requirements for steel pipes, and inability to straighten steel pipe ends, so as to achieve good overall performance and crystal distribution Reasonable and high concentration of performance indicators

Active Publication Date: 2018-12-21
安徽华飞机械铸锻有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] (2) The mechanical properties of the whole tube are quite different
With the improvement of users' requirements for products, it is difficult for this kind of steel pipe with two ends to meet the requirements of users.
And the bending caused by the stress caused by the temperature difference can be straightened. However, the end of the steel pipe cannot be straightened and some seamless steel pipes do not have a suitable straightening machine, resulting in a decline in the yield of the product or even a failure to become a steel pipe due to the inability to complete the straightening. finished product

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A seamless steel pipe heat treatment process is carried out according to the following steps:

[0028] (1) Annealing: First, the semi-finished seamless steel pipe after casting is transported to the muffle furnace for annealing treatment. Before the annealing treatment, the annealing furnace is preheated. At 520°C, the annealing holding time is set to 40min;

[0029] The above-mentioned seamless steel pipe includes the following chemical composition by weight percentage: C 0.21%, Si 0.16%, Mn 0.48%, Ni 0.37%, S 0.01%, P 0.01%, and the balance is Fe and unavoidable impurities, wherein , the content of unavoidable impurities is controlled at ≤0.05%;

[0030] (2) Quenching: The annealed seamless steel pipe is then transported to the quenching furnace for quenching treatment, which is divided into the following three stages:

[0031] The temperature of the heating section is 780°C, and the holding time is 20min;

[0032] The temperature of the second section of heating i...

Embodiment 2

[0037] A seamless steel pipe heat treatment process is carried out according to the following steps:

[0038] (1) Annealing: first transport the semi-finished seamless steel pipe after casting to the muffle furnace for annealing treatment. Before the annealing treatment, preheat the annealing furnace first. At 530°C, the annealing holding time is set to 45min;

[0039] The above-mentioned seamless steel pipe includes the following chemical composition by weight percentage: C 0.25%, Si 0.20%, Mn 0.52%, Ni 0.42%, S 0.015%, P 0.015%, and the balance is Fe and unavoidable impurities, wherein , the content of unavoidable impurities is controlled at ≤0.05%;

[0040] (2) Quenching: The annealed seamless steel pipe is then transported to the quenching furnace for quenching treatment, which is divided into the following three stages:

[0041] The temperature of the heating section is 7890°C, and the holding time is 22 minutes;

[0042] The temperature of the second stage of heating ...

Embodiment 3

[0047] A seamless steel pipe heat treatment process is carried out according to the following steps:

[0048] (1) Annealing: First, the semi-finished seamless steel pipe after casting is transported to the muffle furnace for annealing treatment. Before the annealing treatment, the annealing furnace is preheated. At 540°C, the annealing holding time is set to 50min;

[0049] The above-mentioned seamless steel pipe includes the following chemical composition by weight percentage: C 0.43%, Si 0.24%, Mn 0.60%, Ni 0.60%, S 0.02%, P 0.02%, and the balance is Fe and unavoidable impurities, wherein , the content of unavoidable impurities is controlled at ≤0.05%;

[0050] (2) Quenching: The annealed seamless steel pipe is then transported to the quenching furnace for quenching treatment, which is divided into the following three stages:

[0051] The temperature of the heating section is 80°C, and the holding time is 25 minutes;

[0052] The temperature of the second section of heati...

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PUM

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Abstract

The invention discloses a seamless steel tube heat treatment process. The process comprises the following steps that (1) annealing is conducted, specifically, a semi-finished seamless steel tube is conveyed into a muffle furnace for annealing treatment; (2) quenching is conducted, specifically, the annealed seamless steel tube is conveyed into a quenching furnace for quenching treatment through a first heating stage, a second heating stage and a soaking stage; (3) quenching bath pouring soaking is conducted, specifically, the seamless steel tube is discharged from the quenching furnace after quenching is completed and soaked in quenching bath with the temperature being 15-25 DEG C, and the quenching time is 45-55 s; and (4) tempering is conducted, specifically, finally, the seamless steel tube is conveyed into a tempering furnace for tempering treatment, and the seamless steel tube is discharged from the tempering furnace and air-cooled to the room temperature after tempering is completed. Through the heat treatment process, the stability of the performance of the seamless steel tube can be improved, and meanwhile, the phenomenon that seamless steel tubes cannot be straightened and corrected due to bending and nonuniform mechanical performance caused by heat treatment is avoided.

Description

technical field [0001] The invention relates to the field of manufacturing seamless steel pipes, in particular to a heat treatment process for seamless steel pipes. Background technique [0002] The seamless steel pipe heat treatment process is to heat the seamless steel pipe workpiece to a certain temperature and keep it for a period of time, and then let it cool slowly. Heat treatment of seamless steel pipe is a heat treatment method in which the steel pipe is heated to a temperature at which a phase transition or partial phase transition occurs, and then slowly cooled after heat preservation. The purpose of heat treatment is to reduce hardness, improve plasticity, and improve processing performance; eliminate internal stress, stabilize steel pipe size, place deformation and cracking; refine grains, improve structure, and improve mechanical properties of seamless steel pipes. [0003] At present, when seamless steel pipes are heat treated, after normal heat preservation, ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D9/08C21D1/26C21D1/20C22C38/04C22C38/02C22C38/08
CPCC21D1/20C21D1/26C21D9/08C22C38/02C22C38/04C22C38/08
Inventor 杨胜谢枫
Owner 安徽华飞机械铸锻有限公司
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