Seamless steel pipe hardness testing
Seamless steel pipes generally use three hardness indicators, Brinell, Rockwell, and Vickers to measure their hardness.
1. Brinell hardness
Among the seamless steel pipe standards, Brinell hardness is the most widely used, and the hardness of the material is often expressed by the indentation diameter, which is intuitive and convenient. But it is not suitable for steel pipes of harder or thinner steel.
2. Rockwell hardness
The Rockwell hardness test of seamless steel pipes is the same as the Brinell hardness test, which is an indentation test method. The difference is that it measures the depth of the indentation. Rockwell hardness test is currently a widely used method, among which HRC is second only to Brinell hardness HB in steel pipe standards. Rockwell hardness can be used to measure metal materials ranging from extremely soft to extremely hard. It makes up for the difference of the Brinell method and is simpler than the Brinell method. The hardness value can be read directly from the dial of the hardness machine. However, due to its small indentation, the hardness value is not as accurate as the Brinell method.
3. Vickers hardness
The Vickers hardness test of seamless steel pipes is also an indentation test method, which can be used to determine the hardness of very thin metal materials and surface layers. It has the main advantages of Brinell and Rockwell method, and overcomes their basic shortcomings, but it is not as simple as Rockwell method. Vickers method is rarely used in steel pipe standards.