CN-122015617-A - Method for measuring depth of quenched and tempered layer of alloy steel

Abstract

The invention belongs to the technical field of ferrous metallurgy and relates to a method for measuring the depth of a quenched and tempered alloy steel layer, which comprises the following steps of S1, carrying out full-section sawing and blanking on a quenched and tempered alloy steel material to be measured to obtain a sample, wherein the two sides of the sample are required to be parallel, the thickness of the sample is 1.5-2.5 cm, S2, carrying out rough grinding on one side of the sample by a grinder, S3, carrying out polishing treatment on the rough grinding side of the rough grinding sample, S4, immersing the polished sample in hot acid for corrosion, keeping the temperature at 60-80 ℃ for 20-30 min, S5, carrying out cold acid corrosion on the sample corroded by the hot acid for 1min, then washing by clean water, carrying out cyclic operation for more than 3 times until the surface structure is clear, and then drying, and S6, measuring. The method greatly simplifies the operation flow, improves the measurement efficiency, reduces the operation threshold, can effectively solve the pain points existing in the traditional method, and is suitable for the industrial production requirement.

Inventors

• Hou quan
• YANG GENGCHAO
• ZHANG JIE
• LIU ZHI
• HUANG ZHENHUA
• YUAN LIN
• YUAN YUAN

Assignees

• 湖南华菱湘潭钢铁有限公司

Dates

Publication Date

20260512

Application Date

20260319

Claims (5)

1. 1. A method for measuring the depth of a quenched and tempered layer of alloy steel, comprising the steps of: S1, carrying out full-section sawing and blanking on an alloy steel material subjected to tempering to be measured to obtain a sample, wherein the two surfaces of the sample are required to be ensured to be parallel, and the thickness of the sample is 1.5-2.5 cm; S2, carrying out grinding wheel surface rough grinding on one surface of the sample; s3, polishing the rough polished surface of the sample subjected to rough polishing in the step S2 by a grinder; S4, soaking the polished sample in the step S3 in hot acid for corrosion at 60-80 ℃ for 20-30 min; step S5, carrying out cold acid corrosion on the sample subjected to the hot acid corrosion in the step S4 for 1min, then cleaning with clear water, carrying out cold acid corrosion for 1min and clear water cleaning cycle operation for more than 3 times until the surface tissues are clear, and then drying; And S6, according to different colors displayed by different tissues, displaying the color of the sample treated in the step S5 as black gray, and measuring the black gray depth to obtain the quenched and tempered layer depth of the alloy steel material, wherein the outer ring of the sample close to the surface is a quenched and tempered layer tissue.
2. 2. The method for measuring the depth of a quenched and tempered layer of alloy steel as claimed in claim 1, wherein in the step S2, the surface roughness is 1000 μm.
3. 3. The method for measuring the depth of hardened and tempered alloy steel as claimed in claim 2, wherein in the step S3, the surface roughness is 200 μm.
4. 4. A method for measuring the depth of a hardened and tempered layer of alloy steel as claimed in claim 3 wherein in step S4 the hot acid is hydrochloric acid at a concentration of 30%.
5. 5. The method according to claim 4, wherein in the step S5, the cold acid is a cold etching solution purchased from the institute of new materials of double mines in Wuhan city.

Description

Method for measuring depth of quenched and tempered layer of alloy steel Technical Field The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a method for measuring the depth of a quenched and tempered layer of alloy steel. Background The quenched and tempered alloy steel is a traditional industrial material, and in order to improve the toughness comprehensive performance of the material, the steel is subjected to heat treatment in a quenching and tempering mode, the alloy steel can form a uniform quenched and tempered layer through the process, the strength, toughness and wear resistance of the alloy steel are directly determined by the depth of the quenched and tempered layer, and the service life and operation reliability of key parts of mechanical equipment are further affected, so that accurate measurement of the depth of the quenched and tempered layer of the alloy steel is one of core links of quality control in the fields of ferrous metallurgy and downstream equipment manufacturing. At present, a commonly used quenched and tempered layer depth measuring method in the industry mainly comprises a metallographic microscope observation method and a hardness testing method, wherein the metallographic microscope observation method is used for carrying out destructive treatments such as cutting, embedding, polishing and corrosion on steel, is complex in operation, cannot realize complete measurement of a full section, can only acquire quenched and tempered layer depth data of local points, and is easy to be influenced by distribution of testing points due to the fact that hardness testing rules determine quenched and tempered layer boundaries through hardness gradients of different depths, has large measurement deviation, is difficult to meet high-precision detection requirements, and is especially not suitable for full-section quenched and tempered layer detection of large-size thick-section alloy steel. With the upgrade of high-end equipment manufacturing industry, the requirements of fields such as engineering machinery, nuclear power, aerospace and the like on the performance consistency of quenched and tempered alloy steel are continuously improved, the distribution rule of a full-section quenched and tempered layer of steel is required to be precisely mastered, the existing measuring method has the defects of strong destructiveness, incomplete measurement, insufficient precision and the like, the high-quality control requirements of industrial production cannot be met, and meanwhile, nondestructive detection equipment is mostly suitable for thin-surface or local detection, and the full-section precise measurement is difficult to realize. Under the background, a method capable of realizing full-section, high-precision and high-efficiency measurement of the depth of the quenched and tempered alloy steel layer is developed, and the method becomes an urgent need for solving the bottleneck of the prior art and pushing the high-quality development of the quenched and tempered alloy steel industry. Disclosure of Invention Aiming at the current situation that the depth of a quenched and tempered layer is complicated and incomplete, the invention provides a method for measuring the depth of the quenched and tempered layer of alloy steel, wherein most of the alloy steel is quenched and tempered, a quenched and tempered layer with high strength and high toughness is formed on the surface of the steel after quenching and tempering, the quenched and tempered layer mainly comprises tempered sorbite and ferrite, the tissue grade is less than or equal to 4 grade, the conventional measurement of the depth of the quenched and tempered layer is small in cutting sample, the width is 2mm x to 3mm, the acid corrosion is carried out after repeated polishing and polishing, and the depth of the quenched and tempered layer is measured according to the condition of metallographic observation tissue. The technical scheme adopted by the invention is that the method for measuring the depth of the quenched and tempered layer of the alloy steel comprises the following steps: S1, carrying out full-section sawing and blanking on an alloy steel material subjected to tempering to be measured to obtain a sample, wherein the two surfaces of the sample are required to be ensured to be parallel, and the thickness of the sample is 1.5-2.5 cm; S2, carrying out grinding wheel surface rough grinding on one surface of the sample; s3, polishing the rough polished surface of the sample subjected to rough polishing in the step S2 by a grinder; S4, soaking the polished sample in the step S3 in hot acid for corrosion at 60-80 ℃ for 20-30 min; step S5, carrying out cold acid corrosion on the sample subjected to the hot acid corrosion in the step S4 for 1min, then cleaning with clear water, carrying out cold acid corrosion for 1min and clear water cleaning cycle operation for more than 3 times until the surfa