A kind of preparation method of crmo alloy steel forged circle resistant to low temperature impact

A low-temperature-resistant, alloy steel technology, applied in the field of preparation of low-temperature impact-resistant CrMo alloy steel forging circles, can solve the problems of difficult to guarantee product quality and unattainable alloys, reduce deformation and cracking tendency, improve yield, The effect of good strength and toughness

Active Publication Date: 2020-09-22
JIANGSU ZHUHONG FORGING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In deep oil mining, the impact toughness Akv of the alloy steel drill pipe at a low temperature of -60°C is required to be above 30J. The alloy produced by the above process cannot meet the above requirements, and the product quality is difficult to be guaranteed.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] The preparation method provided by this invention is used to process the typical CrMo steel ingot with the American brand AISI 4130. The single weight of the prepared steel ingot is 5 tons, and the equivalent average diameter is 558mm. After heating + forging + air cooling + normalizing + Rough turning + quenching and tempering treatment to produce a CrMo alloy steel forged circle with a diameter of 310mm. Its manufacturing method is:

[0038] S1, heating up. Heat the steel ingot to 600°C, keep it warm for 1.5 hours, then heat it to 800°C, keep it warm for 0.5 hours, then heat it to a malleable 1180°C, and keep it warm for 3 hours, so that the surface and internal temperature of the steel ingot are basically the same. The body tissue is homogenized.

[0039] S2, forging and pressing. Hoist the heated steel ingot to the forging press to start forging, first forge it into a square shape, then press its edges, and finally forge it into a cylindrical forging circle with ...

Embodiment 2

[0054] S1, heating up. Heat the steel ingot to 700°C, keep it warm for 2.5 hours, then heat it to 830°C, keep it warm for 1.5 hours, then heat it to a malleable 1200°C, and keep it warm for 4.5 hours, so that the surface and internal temperature of the steel ingot are basically the same. The body tissue is homogenized.

[0055] S2, forging and pressing. Hoist the heated steel ingot to the forging press to start forging, first forge it into a square, then press its edges, and finally forge it into a cylindrical forging circle with a certain length and target diameter, control the forging ratio at 3.5:1, and control the forging The temperature is 1000°C.

[0056] S21, removing iron oxide. The pre-designed forging round iron oxide cleaning machine is used to continuously remove the iron oxide on the surface of the red hot forging billet during the forging process, thereby greatly improving the surface quality of the forged red hot forging billet. The forged round surface is sm...

Embodiment 3

[0070] S1, heating up. Heat the steel ingot to 750°C, keep it warm for 3.5 hours, then heat it to 850°C, keep it warm for 2.5 hours, then heat it to a malleable 1230°C, then keep it warm for 6.5 hours, so that the surface and internal temperature of the steel ingot are basically the same, and the austenite in the steel ingot The body tissue is homogenized.

[0071] S2, forging and pressing. Lift the heated steel ingot to the forging press to start forging, first forge it into a square shape, then press its edges, and finally forge it into a cylindrical forging circle with a certain length and target diameter, control the forging ratio at 4:1, and control the forging The temperature is 1200°C.

[0072] S21, removing iron oxide. The pre-designed forging round iron oxide cleaning machine is used to continuously remove the iron oxide on the surface of the red hot forging billet during the forging process, thereby greatly improving the surface quality of the forged red hot forgi...

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Abstract

The invention relates to the technical field of CrMo alloy steel forging, in particular to a method for preparing a low-temperature impact resistance CrMo alloy steel forged round bar. The preparationobjects comprise alloy steel with the trade mark being AISI 4130, alloy steel with the trade mark being 4130 and alloy steel with the trade mark being 30CrMo. The technological process adopted includes the steps that a steel ingot is subjected to multistage heating until the temperature is 1180-1230 DEG C, and heat preservation lasts for 3-6.5h; then forging formation is conducted at the temperature of 1200-800 DEG C, and air cooling is executed; and afterwards, normalizing at the temperature of 900+ / -10 DEG C, underwater quenching at the temperature of 880+ / -10 DEG C and high-temperature tempering at the temperature of 670+ / -10 DEG C are carried out, and a tempered sorbite structure with good overall performance can be obtained inside the forged round bar. The technical requirement thatimpact toughness Akv needs to reach 30J or above in the low-temperature environment of -60 DEG C is effectively met.

Description

technical field [0001] The invention relates to the technical field of CrMo alloy steel forging processing, in particular to a method for preparing a low-temperature impact-resistant CrMo alloy steel forging circle. Background technique [0002] The alloy steel of CrMo belongs to the steel used for oil drill pipes. When used, the drill pipes are connected to each other through threaded openings and gradually extend to the deep underground, so as to meet the needs of oil exploitation. [0003] The Chinese patent with the notification number CN103990758B discloses a manufacturing process for 10Cr9Mo1VNb steel forgings, which includes the following steps: (1) heating the 10Cr9Mo1VNb steel forgings at a heating temperature of 850-1250°C; Forging of the 10Cr9Mo1VNb steel forgings; (3), the first normalizing and tempering of the forged 10Cr9Mo1VNb steel forgings; (4), the second normalizing and tempering of the 10Cr9Mo1VNb steel forgings after the first normalizing and tempering ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D8/06C21D1/28C21D1/18C21D1/58C21D6/00
CPCC21D1/18C21D1/28C21D1/58C21D6/004C21D6/005C21D6/008C21D8/065
Inventor 徐国庆
Owner JIANGSU ZHUHONG FORGING
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