Surface quality control method for vanadium-containing high-nitrogen round steel

A control method and surface quality technology, applied in the field of iron and steel metallurgical processing, can solve problems that affect product quality, lack of surface quality research on vanadium-containing high-nitrogen steel, and easy surface cracks

Active Publication Date: 2021-08-24
BAOSTEEL SPECIAL STEEL SHAOGUAN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above-mentioned previous patents of the inventor only studied the composition improvement and mechanical performance improvement, but did not study the surface quality of vanadium-containing high-nitrogen steel
[0004] However, during the continuous casting, heating, rolling and other production processes of vanadium-containing high-nitrogen steel, surface cracks are likely to occur due to the influence of cooling and heating microstructure phase transformation and thermal stress, which affects product quality.
At present, due to the influence of many factors affecting the surface quality of steel products in the production process, it is difficult to quickly find a method to accurately control the surface quality of vanadium-containing high-nitrogen round steel

Method used

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  • Surface quality control method for vanadium-containing high-nitrogen round steel
  • Surface quality control method for vanadium-containing high-nitrogen round steel
  • Surface quality control method for vanadium-containing high-nitrogen round steel

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Effect test

Embodiment 1

[0049] This embodiment provides a method for controlling the surface quality of vanadium-containing high-nitrogen steel, wherein the composition of the vanadium-containing high-nitrogen steel is shown in Table 1, which includes the following steps:

[0050] (1) In the production of continuous casting slabs, the secondary cooling water adopts a weak cooling method, and the cooling intensity is set at 0.23±0.02L / kg;

[0051] (2) Put the continuous casting slab into the slow cooling pit, the temperature of the continuous casting slab is controlled at 760-811°C when entering the pit, the cooling time in the pit is 76h, and the temperature out of the pit is 150°C;

[0052] (3) Use the Gleeble simulation testing machine to conduct high-temperature tensile tests to obtain a crack-sensitive temperature range of 580-660°C;

[0053] (4) For the surface inspection process of continuous casting slabs, visually check whether there are cracks on the surface and corners of each slab. Cracks...

Embodiment 2

[0059] The composition of vanadium-containing high-nitrogen steel is as shown in Table 1, and it comprises the following steps:

[0060] (1) In the production of continuous casting slabs, the secondary cooling water adopts a weak cooling method, and the cooling intensity is set at 0.23±0.02L / kg;

[0061] (2) Put the continuous casting slab into the slow cooling pit, the temperature of the continuous casting slab is controlled at 772-807°C when entering the pit, the cooling time in the pit is 80h, and the temperature out of the pit is 113°C;

[0062] (3) For the surface inspection process of continuous casting slabs, visually check whether there are cracks on the surface and corners of each slab. Cracks; if cracks are found by visual inspection or low-magnification samples, peel the billets one by one (single-side peeling ≥ 3mm);

[0063] (4) Conduct surface inspection on the continuous casting slab to be heated, adopt four-stage heating control, and perform preheating, first-...

Embodiment 3

[0068] The composition of vanadium-containing high-nitrogen steel is as shown in Table 1, and it comprises the following steps:

[0069] (1) In the production of continuous casting slabs, the secondary cooling water adopts a weak cooling method, and the cooling intensity is set at 0.23±0.02L / kg;

[0070] (2) Put the continuous casting slab into the slow cooling pit, the temperature of the continuous casting slab is controlled at 781-820°C when entering the pit, the cooling time in the pit is 86h, and the temperature out of the pit is 87°C;

[0071] (3) For the surface inspection process of continuous casting slabs, visually check whether there are cracks on the surface and corners of each slab. Cracks; if cracks are found by visual inspection or low-magnification samples, peel the billets one by one (single-side peeling ≥ 3mm);

[0072] (4) Conduct surface inspection on the continuous casting slab to be heated, adopt four-stage heating control, and perform preheating, first-s...

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Abstract

The invention discloses a surface quality control method for vanadium-containing high-nitrogen round steel, and belongs to the field of ferrous metallurgy processing. The control method comprises the following steps of testing a crack sensitive temperature interval before heating a continuous casting billet, designing a preheating system of the continuous casting billet according to a measurement result, controlling the highest temperature T3 of a preheating section to be greater than or equal to T2+150 DEG C, controlling the heating rate of the preheating section to be less than or equal to 9 DEG C / min, then matching with a pit-entering slow cooling process of the continuous casting billet and rolled round steel, and finally, the round steel with the surface magnetic flux leakage initial inspection qualified rate reaching 85% or above is obtained.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgical processing, and in particular relates to a method for controlling the surface quality of vanadium-containing high-nitrogen round steel. Background technique [0002] Vanadium-containing high-nitrogen steel is a kind of non-quenched and tempered steel, which has certain strength, toughness, heat treatment-free energy-saving and environmental protection characteristics, but is highly sensitive to cracks, and is widely used in crankshafts, connecting rods and construction machinery of automobile engines. [0003] In the patent CN111286670A, the inventor improved and regulated the composition and content of the medium-carbon non-quenched and tempered steel, and limited the range of the brittleness value K of the medium-carbon non-quenched and tempered steel by the carbon equivalent value, phosphorus content and copper content , so that the medium-carbon non-quenched and tempered steel has l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21D9/52C21D6/00C21D11/00C22C38/00C22C38/02C22C38/04C22C38/06C22C38/12C22C38/16G01N3/18G01N27/83
CPCC21D9/52C21D11/00C21D6/005C21D6/008C22C38/02C22C38/04C22C38/06C22C38/001C22C38/12C22C38/16G01N3/18G01N27/83G01N2203/0003G01N2203/0017G01N2203/0067G01N2203/0226G01N2203/0676G01N2203/0694
Inventor 刘年富钟芳华周成宏赵贺楠胡昭锋杨伟光董凤奎廖美华
Owner BAOSTEEL SPECIAL STEEL SHAOGUAN CO LTD
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