Simply speaking, it is to pierced stainless steel ingots or stainless steel solid billets to form capillary pipes, and then to make them by hot rolling, cold rolling or cold dialing. There are mainly three kinds of hardness of stainless steel pipes. This paper will introduce them.
Rockwell hardness
The Rockwell hardness test of stainless steel pipe is the same as that of Brinell hardness test, all of which are indentation test. The difference is, Rockwell hardness testing method is to measure the depth of the indentation, this is a kind of method uses a lot of current, in which HRC stainless steel pipe standard application after HB Brinell hardness, Rockwell hardness can be applied to the determination of metal materials from soft to hard, this method makes up the deficiency of Brinell hardness method the detection method is more convenient than the Brinell hardness machine, can be directly read out from the dial hardness. However, because the smaller indentation variant of the method, so the accuracy is worse than that of Brinell hardness method.
Brinell hardness
In the standard of stainless steel pipe, Brinell hardness is the most widely used. Usually, indentation diameter is used to explain the hardness of testing materials, which is not only intuitive and convenient, but not suitable for hard or thin steel pipes.
Vickers hardness
Vivtorinox is also an indentation hardness test detection method can be used to detect metal thin layer and surface hardness, including Brinell and Rockwell two methods advantages, and also remove the basic shortcomings of the two, but the defect is not Rockwell convenient, Vivtorinox detection method in the application of the standard stainless steel pipe many.
So many methods of hardness testing are said, and then the specific testing of the stainless steel is described in detail. When the inner diameter of the stainless steel pipe is above 6.0mm, the annealed stainless steel pipe under the wall thickness of 13mm can be used W-B75 type Wechsler hardness tester. Its detection is fast and convenient. It is suitable for fast and nondestructive testing of stainless steel pipes. Stainless steel pipe with inner diameter of stainless steel pipe is higher than 30mm, and the wall thickness is more than 1.2mm. The hardness of HRB and HRC is tested by Rockwell hardness tester. Stainless steel pipe diameter greater than 30mm, wall thickness less than 1.2mm stainless steel pipe, using surface Rockwell hardness test HRT or HRN hardness, diameter less than 0mm, more than 4.8mm stainless steel pipe, the pipe Rockwell hardness test the hardness of HR15T stainless steel, when the pipe diameter is more than 26mm, can also use Rockwell or surface Rockwell hardness test stainless steel wall.
Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)
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