Stainless steel welded pipe production process: Raw material - article points - welding pipe - repair end - polishing - inspection (purchase) - packaging - shipment (transport) welded pipe (decoration) raw material - article points - welding pipe - heat treatment - correction, straightening, fix the end - acid - water pressure test, inspection (spurts India) - packaging - shipment (transport) (tube) for piping weld pipe industry hardness Stainless steel pipes are generally used to measure the hardness of Brinell, Rockwell, Vickers three hardness indicators. Brinell hardness in stainless steel pipe standards, brinell hardness is the most widely used, often to indentation diameter to indicate the hardness of the material, both intuitive and convenient. However, it is not suitable for steel pipes of harder or thinner steel. The Rockwell hardness test of stainless steel pipe is the same as the Brinell hardness test, which is an indentation test method. The difference is that it measures the depth of the indentation. Rockwell hardness test is a widely used method at present, and HRC is second only to Brinell hardness HB in steel pipe standards. Rockwell hardness can be applied to the determination of very soft to very hard metal materials, it makes up for the Brinell method is not, is simpler than the Brinell method, can directly read the hardness value from the dial of the hardness machine. However, due to the small indentation, the hardness value is not as accurate as the Brinell method. The Vickers hardness test is also an indentation test method that can be used to determine the hardness of very thin metal materials and surface layers. It has the main advantages of Brinell and Rockwell method, and overcomes their basic shortcomings, but it is not as simple as Rockwell method, and Vickers method is rarely used in steel pipe standards. For annealed stainless steel pipes with inner diameter above 6.0mm and wall thickness below 13mm, W-B75 Wechsler hardness tester can be used, which is very fast and easy to test and suitable for rapid and non-destructive qualification inspection of stainless steel pipes. For stainless steel pipes with inner diameter greater than 30mm and wall thickness greater than 1.2mm, Rockwell hardness tester is used to test HRB and HRC hardness. Stainless steel pipes with inner diameter greater than 30mm and wall thickness less than 1.2mm are tested for HRT or HRN hardness using a surface Rockwell hardness tester. For stainless steel pipes with inner diameter less than 0mm and greater than 4.8mm, Rockwell hardness tester for pipes is used to test HR15T hardness. When the inner diameter of the stainless steel pipe is greater than 26mm, the hardness of the inner wall of the pipe can also be tested with Rockwell or surface Rockwell hardness tester.
