In the production process of steel pipes, whether it is a seamless pipe or a
casing pipe, it is often necessary to measure the degree of completion of the processing of the steel pipe and the adjustment of the process and the adjustment of the heat treatment by measuring the hardness of the steel pipe, so that the performance of the steel pipe meets the requirements of the customer. index of. The hardness of
seamless steel tubes is generally measured by three hardness indexes: Brinell, Rockwell and Vickers. Today we will talk about the hardness measurement of steel pipes.
In the steel pipe standard, the Brinell hardness of the steel pipe is the most widely used, and the hardness of the material is often expressed by the indentation diameter, which is intuitive and convenient. However, it is not suitable for hard or thin steel pipes.
The Rockwell hardness test of steel pipes is the same as the Brinell hardness test. The difference is that it measures the depth of the indentation. The Rockwell hardness test of steel pipes is currently widely used, and HRC is used in steel pipe standards only after Brinell hardness HB. Rockwell hardness can be applied to the determination of metal materials from very soft to very hard, which makes up for the shortcomings of the Brinell method. It is simpler than the Brinell method and can directly read the hardness value from the dial of the hardness machine. However, due to its small indentation, the hardness value is not as accurate as the Brinell method.
The Vickers hardness test of steel pipes is also an indentation test method for measuring the hardness of very thin metal materials and surface layers. It has the main advantages of Brinell and Rockwell methods, and overcomes their basic shortcomings, but it is not as simple as the Rockwell method. The Vickers method is rarely used in steel pipe standards.
