Knowledge of hardness of stainless steel pipes

1. The W-B75 Vickers hardness tester can be used for materials with inner diameters greater than 6.0mm and wall thicknesses less than 13mm for hardness testing of annealed stainless steel pipes. It is very fast and simple, and is suitable for rapid non-destructive qualification testing of stainless steel pipe materials. Stainless steel pipes with an inner diameter greater than 30 millimeters and a wall thickness greater than 1 or 2 millimeters should undergo HRB and HRC hardness testing using a Rockwell hardness tester. For stainless steel pipes with an inner diameter greater than 30 millimeters and a wall thickness less than 1 or 2 millimeters, a surface Rockwell hardness tester should be used to test the HRT or HRN hardness. For stainless steel pipes with an inner diameter less than 0 millimeters but greater than 4 or 8 millimeters, a pipeline specific Rockwell hardness tester should be used to test the HR15T hardness. When the inner diameter of the stainless steel pipe is greater than 26 millimeters, the hardness of the inner wall of the pipe can also be tested using a Rockwell or surface Rockwell hardness tester.

2. The Vickers hardness test for stainless steel pipes is also an indentation test method that can be used to measure the hardness of very thin metal materials and surfaces. It has the main advantages of the Brinell method and the Rockwell method, but overcomes their basic disadvantages, but is not as simple as the Rockwell method, and the Vickers method is rarely used in steel pipe standards.

3. The Rockwell hardness test for stainless steel pipes, like the Brinell hardness test, is an indentation test method. The difference is that it is used to measure the depth of indentation. The Rockwell hardness test is currently a widely used method. HRC is second only to Brinell hardness HB in steel pipe standards. Rockwell hardness can be used to measure metal materials ranging from soft to very hard, making up for the shortcomings of the Brinell method and being simpler than the Brinell method. The hardness value can be directly read from the dial of the hardness machine. However, due to the small indentation, the hardness value is not as accurate as the Brinell method.