Hardness of ERW Tube

Main hardness of erw tube: Vickers hardness method can be used for the determination of thin metal materials and the surface layer hardness. It has the main advantages of brinell, rockwell, and overcome their basic shortcomings, but not as easy as rock's law vickers' method is seldom used in the standard of steel pipe.In the standard of steel pipe, brinell hardness is the most widely used, and the indentation diameter d is often used to indicate the hardness from the  material, which is both intuitive and convenient. From extremely soft to extremely hard metal material, it makes up for the Brinell method is not, compared with the Brinell method is simple, can be directly read from the dial of the hardness machine.But because of its indentation, the hardness value is not as good as the cloth law accurate.

The vickers hardness test of erw tube is introduced: Vickers hardness test is an indentation test method, is a relative angle of 1360 square pyramid diamond surface with a selected test force (F) pressed into the test surface , After the provisions of the time to remove the test force, measuring the indentation diagonal length. Vickers hardness is the test force divided by the indentation surface area derived from the business, which is calculated as: HV - Vickers hardness symbols, N / mm2 (MPa); F - test force, N; d - pressure Arithmetic mean of two diagonals, mm. Vickers hardness test force F is 5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50 (490.3), 100 (980.7) Kgf (N) P> value range of 5 ~ 1000HV.