The hardness test of stainless steel should take into account its mechanical properties, which is related to the performance and quality of deformation, stamping, cutting and other processing using stainless steel as a raw material. Therefore, all seamless steel tubes must be tested for mechanical properties. So what is the hardness testing method of seamless steel tubes, the mechanical property testing methods are mainly divided into two categories, one is the tensile test, and the other is the hardness test.
The tensile test is to make a seamless steel tube into a sample, pull the sample to break on a tensile test machine, and then measure one or several mechanical properties, usually only the tensile strength, yield strength, elongation after break and rate of reduction in area. Tensile test is the most basic mechanical property test method for metal materials. Almost all metal materials, as long as there are requirements for mechanical properties, all provide tensile tests. Especially for materials whose shape is not convenient for hardness testing, tensile testing becomes the only means of testing mechanical properties.
The hardness test is to slowly press a hard indenter into the sample surface with a hardness tester according to the specified conditions, and then test the depth or size of the indentation to determine the hardness of the material. The hardness test is the simplest, fastest and easiest method to perform in the mechanical properties test of materials. The hardness test is non-destructive, and there is an approximate conversion relationship between the material hardness value and the tensile strength value. The hardness value of the material can be converted into a tensile strength value, which has great practical significance.
Because the tensile test is not easy to test, and it is very convenient to convert from hardness to strength, people are increasingly testing only the hardness of the material and less testing its strength. In particular, due to the continuous advancement and innovation of the hardness tester manufacturing technology, some materials that could not be directly tested for hardness, such as seamless steel tubes, stainless steel plates and stainless steel bands, are now possible to directly test the hardness. Therefore, there is a tendency that the hardness test gradually replaces the tensile test.
Most of the national standards for stainless steel materials specify both tensile test and hardness test. For those materials that are not convenient for hardness testing, such as seamless steel tubes, only tensile tests are specified. In the stainless steel standard, three hardness test methods of cloth, luo, and wei are generally specified to determine the hardness values ​​of HB, HRB (or HRC), and HV, and only one of the three hardness values ​​is required. In particular, the latest portable surface Rockwell hardness tester and pipe Rockwell hardness tester can quickly and accurately test the hardness of stainless steel plates, stainless steel strips as thin as 0.05mm, and seamless steel tubes as thin as ï¿ 4.8mm. Problems that are difficult to solve in China are solved.
Silver Mirror,Round Silver Mirror,Silver Standing Mirror,Mini Transparent Silver Mirror
Dongguan Huahui Glass Manufacturing Co.,Ltd , https://www.antiquemirrorsupplier.com