Generally, three kinds of hardness indicators, Brinell, Rockwell and Vickers, are used to measure the hardness of seamless steel pipes.
1.Brinell hardness tester
In the seamless steel pipe standard, Brinell hardness is the most widely used, and the hardness of the material is often expressed by the diameter of the indentation, which is intuitive and convenient. However, it is not suitable for steel pipes of harder or thinner steel.
The Rockwell hardness test of seamless steel pipes is the same as the Brinell hardness test, and is an indentation test method. The difference is that it measures the depth of the indentation. The Rockwell hardness test is a widely used method at present, in which HRC uses the steel pipe standard after Brinell hardness HB. The Rockwell hardness can be applied to the determination of extremely soft to extremely hard metal materials. It makes up for the Brinell method and is simpler than the Brinell method. It can read the hardness value directly from the dial of the hardness machine. However, because its indentation is small, the hardness value is not as accurate as the Brinell method.
The Vickers hardness test of seamless steel pipes is also an indentation test method that can be used to determine the hardness of very thin metal materials and surface layers. It has the main advantages of the Brinell and Rockwell methods, but overcomes their basic disadvantages, but it is not as simple as the Rockwell method, and the Vickers method is rarely used in steel pipe standards.
Post time: Jan-06-2020