Stainless steel pipe is a long, hollow round steel, widely used in many industries. Its hardness can be divided into the following three types:
Rockwell hardness
The Rockwell hardness test of the stainless steel pipe is the same as the Brinell hardness test, which is the indentation test method. The difference is that it is to measure the depth of the slit. The Rockwell hardness test is currently a widely used method. Among them, the HRC is used in steel pipe standards only surpassed by Brinell HB hardness, and Rockwell hardness can be applied to determine from very soft metal material to extremely hard metal, compensates for the Brinell method, which is simpler than the Brinell method, and the hardness value can be read directly on the hardness machine dial. However, due to its small slit, the hardness value is not as accurate as the Brinell method.
Brinell Hardness
Among stainless steel pipe standards, Brinell hardness is the most widely used. The hardness of the material is often expressed by the diameter of the slit, which is intuitive and convenient, but is not suitable for harder or thinner steel pipes.
Vickers Hardness
The Vickers hardness test of stainless steel pipes is also an indentation test method, which can be used to determine the hardness of very thin metallic materials and surface layers. It has the main advantages of the Brinell and Rockwell methods, and overcomes its basic deficiencies, but it is not as good as Luo The Vickers method is simple, and the Vickers method is rarely used in steel pipe standards.
Hardness test
For stainless steel pipes with internal diameters greater than 6.0 mm and wall thicknesses less than 1.3 mm, the Webster W-B75 hardness tester can be used. It is very fast and easy to test, and is suitable for fast and non-destructive stainless steel qualification inspections. steel pipes. For stainless steel pipes with an inner diameter greater than 30 mm and a wall thickness greater than 1.2 mm, the Rockwell hardness tester is used to test HRB and HRC hardness. Stainless steel tubes with an inner diameter greater than 30 mm and a wall thickness of less than 1.2 mm use a rockwell surface hardness tester to test HRT or HRN hardness. Stainless steel pipes with an inner diameter of less than 0 mm and greater than 4.8 mm use a special Rockwell hardness pipe tester to test HR15T hardness, when the inner diameter of the stainless steel pipe is greater than 26 mm, the hardness of the inner pipe wall can also be tested with a Rockwell hardness tester or Rockwell surface tester.
