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Vickers hardness and Rockwell hardness conversion method for 8Cr4Mo4V steel

A technology of 8cr4mo4v and Rockwell hardness, applied in the field of conversion, can solve the problems of error, low data reliability, lack of conversion method between Vickers hardness and Rockwell hardness, etc.

Inactive Publication Date: 2017-12-01
AVIC HARBIN BEARING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the existing error in converting Vickers hardness into Rockwell hardness according to the standard GB / T1172-1999 "Conversion Value of Ferrous Metal Hardness and Strength" in the hardness test process of small bearing parts made of 8Cr4Mo4V steel, and the data is reliable In view of the problems of low stability and lack of conversion method between Vickers hardness and Rockwell hardness in the prior art, a conversion method between Vickers hardness and Rockwell hardness for 8Cr4Mo4V steel is proposed

Method used

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  • Vickers hardness and Rockwell hardness conversion method for 8Cr4Mo4V steel
  • Vickers hardness and Rockwell hardness conversion method for 8Cr4Mo4V steel

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specific Embodiment approach 1

[0024] Specific embodiment one: this embodiment is used for the Vickers hardness of 8Cr4Mo4V steel and the conversion method of Rockwell hardness is carried out according to the following steps:

[0025] 1. Preparation of testing samples:

[0026] ①High hardness value sample: the Rockwell hardness range of the high hardness value sample is 55~63HRC and 63~70HRC; the high hardness value sample with the Rockwell hardness range of 55~63HRC is tempered. 8Cr4Mo4V quenched steel with a Rockwell hardness range of 63 to 70HRC is 8Cr4Mo4V quenched steel with a Rockwell hardness of 63 to 70HRC; 8Cr4Mo4V quenched steel with a Rockwell hardness of 63 to 70HRC

[0027] The tempering process is tempering three times at 550-600° C., and the tempering time is 2-3 hours each time;

[0028] ② Medium hardness sample: select 8Cr4Mo4V quenched steel with a Rockwell hardness of 30-55HRC, and temper the quenched steel as a medium hardness sample; the tempering process is: at a temperature of 600 ° ...

specific Embodiment approach 2

[0039] Specific embodiment two: the difference between this embodiment and specific embodiment one is that the Rockwell hardness tester described in step 2 is calibrated according to the standard ASTM E18 "Standard Test Method for Rockwell Hardness of Metal Materials"; : High hardness value samples use 61.5HRC hardness blocks; medium hardness value samples use 47.6HRC hardness blocks and 35.1HRC hardness blocks; low hardness value samples use 21.6HRC hardness blocks; calibration hardness testers use C standard, The loading load is 150Kgf, the indoor ambient temperature is 10℃~35℃ and the humidity is ≤60%. Other steps and parameters are the same as those in the first embodiment.

specific Embodiment approach 3

[0040] Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that the Vickers hardness tester described in step 2 is calibrated according to the standard ASTM E92 "Metal Material Vickers Hardness Test Method"; the hardness block is selected during calibration The standard is: 743HV1 hardness block is used for samples with high hardness value; 433HV1 hardness block is used for samples with medium hardness value; Humidity is ≤60%. Other steps and parameters are the same as those in Embodiment 1 or 2.

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Abstract

The invention relates to a Vickers hardness and Rockwell hardness conversion method for 8Cr4Mo4V steel and aims to solve the problems that during the hardness tests of existing 8Cr4Mo4V steel small bearing parts, errors exist when the Vickers hardness is converted into the Rockwell hardness according to the standards GB / T1172-1999 Black Metal Hardness and Strength Conversion Value, data reliability is low, and the prior art does not have a Vickers hardness and Rockwell hardness conversion method. The method includes the steps of firstly, preparing a detection sample; secondly, calibrating hardness testers and determining indication errors; thirdly, collecting sample hardness data, and performing conversion according to a formula as shown in the specification. The Vickers hardness and Rockwell hardness conversion method has the advantages that the method aims at the 8Cr4Mo4V steel small bearing parts and uses the actually detected sample data of the Rockwell hardness tester and the Vickers hardness tester to achieve Vickers hardness and Rockwell hardness conversion; the obtained conversion data is identical with the actually detected data, errors are small, and high data reliability is achieved.

Description

technical field [0001] The invention relates to a conversion method. Background technique [0002] The Rockwell hardness of bearing parts has a lot to do with the heat treatment process. Rockwell hardness is an important indicator for evaluating the correctness of the heat treatment process of bearing parts, judging the quality of products and scientific experiments. Therefore, hardness testing has become a common method in mechanical performance tests. a method of At the same time, the results of hardness testing can sensitively reflect the differences in chemical composition, structure and processing technology of materials. are widely used. [0003] In general product drawings, the technical parameters of heat-treated bearing parts have hardness requirements, which are marked with Rockwell hardness values. In actual production, the hardness test of small bearing parts is to fix the parts by mosaic method, and then After the inlaid parts are subjected to grinding and po...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/44G01N3/42
CPCG01N3/44G01N3/42G01N2203/0078
Inventor 班君刘秀莲罗燕张兴洪周淑梅刘雨健徐雷
Owner AVIC HARBIN BEARING
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