The hardness of SSAW steel pipe is the ability of metal materials to resist the indentation of the surface of hard objects. According to the test methods and scope application, hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. There are three commonly used in steel pipes: Brinell, Rockwell and Vickers hardness. Below we will detailed introduce you Brinell hardness.

Brinell hardness (HB) Use a steel ball or cemented carbide ball with a certain diameter and press it into the surface of the sample with the specified test force (F). After the specified holding time, remove the test force and measure the indentation diameter (L ) The Brinell hardness value is the quotient obtained by dividing the test force by the indentation spherical surface area.

Expressed in HBS (steel ball), the unit is N/mm2 (MPa, and the calculation formula is in the formula: F--test force pressed into the surface of the metal sample, N; D--test steel ball diameter, mmd--pressure Average diameter of the trace, mm. It is more accurate and reliable to determine the Brinell hardness, but generally HBS is only suitable for metal materials below 450N/mm2 (MPa).

Brinell hardness is the most widely used for steel pipes, and the hardness of the material is often expressed by the indentation diameter d, which is intuitive and convenient. Example: 120HBS10/1000130: indicates that the Brinell hardness value measured by a steel ball with a diameter of 10mm under a test force of 1000Kgf (9.807KN) for 30s (seconds) is 120N/mm2 (MPa).