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How should I test the hardness of stainless steel seamless steel pipe?

How should I test the hardness of stainless steel seamless steel pipe?

Time:2022-03-18 Source:China Wuxi JiaNuo Special Steel Co.

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In the process of using stainless steel seamless pipe, it is very important to conduct a reasonable hardness test, so how to use the correct method to test the hardness of stainless steel seamless pipe?

Mechanical properties of the test method is mainly divided into two kinds, one is the tensile test, the other is the hardness test. Tensile test is to make a specimen of stainless steel tube, stretch the specimen on a tensile testing machine to make it break, and then measure one or more mechanical properties, usually measuring only tensile strength, yield strength, elongation after break and shrinkage at the section. Tensile testing is the basic mechanical property test method for metallic materials.

Tensile tests are specified for almost all metallic materials, as long as they have requirements for mechanical properties. Especially for materials whose shape does not facilitate hardness testing, the tensile test has become a mechanical property test method. Hardness testing involves slowly pressing a hard indenter into the surface of a sample under specific conditions and then testing the depth or size of the indentation to determine the hardness of the material. Hardness testing is a simple, fast and easy to perform method for testing the mechanical properties of materials. The hardness test is non-destructive and there is an approximate conversion relationship between the hardness value of the material and the tensile strength value.

The hardness value of a material can be converted into a tensile strength value, which is of great practical importance. Since tensile tests are not easy to test and converting hardness to strength is convenient, more and more people test only the hardness of a material and rarely its strength.

Especially due to the continuous progress of hardness tester manufacturing technology and innovation, some materials that cannot be tested for hardness directly, such as stainless steel tubes, stainless steel plates and stainless steel strips, can now be tested for hardness directly. Therefore, there is a trend for hardness testing to gradually replace tensile testing. Most of the national standards for stainless steel materials are specified in the tensile test and hardness test .

For materials that do not facilitate hardness testing, such as stainless steel tubing, only tensile testing is specified. In stainless steel standards, there are usually three hardness test methods cloth, lo and size for measuring hemoglobin, HRB (or high hardness value) and high hardness value, and only one of the three hardness values is required.

Therefore, when testing the hardness of stainless steel seamless tubes, it is necessary to do these details to ensure its good performance.