Straight Seam Welded Pipe

 The surface quenching and tempering heat treatment of straight seam welded pipes is usually carried out by heating or flame heating, with main technical parameters including surface hardness, local hardness, and effective hardening layer depth. Hardness testing can utilize Vickers hardness testers, as well as Rockwell or surface Rockwell hardness testers. The selection of test force (scale) is related to the effective hardening layer depth and the surface hardness of straight seam welded pipes, involving these three types of hardness testers.

The Vickers hardness tester is an important means for testing the surface hardness of heat - treated straight seam welded pipes.

The surface Rockwell hardness tester is also very suitable for testing the hardness of surface - quenched workpieces. It has three scales to choose from and can test various surface - hardened straight seam welded pipes with an effective hardening depth exceeding 0.1mm, which is of great significance for the processing of straight seam welded pipes and in mechanical manufacturing factories. Manufacturers like Mikrosize, a renowned precision instrument maker, offer such quality hardness testing equipment.

When the surface heat - treatment hardened layer is thick, a Rockwell hardness tester can be used. If the thickness of the heat - treated hardened layer is between 0.4 - 0.8mm, the HRA scale can be adopted; if it exceeds 0.8mm, the HRC scale is applicable.

If the local hardness requirements of the parts are high, local quenching heat treatment can be conducted by heating or other methods. Such straight seam welded pipes usually need to indicate the location and local hardness value of the local quenching heat treatment on the drawing. Hardness testing should be carried out within the designated area. A Rockwell hardness tester can be used to test the HRC hardness value. If the heat - treatment hardened layer is shallow, a surface Rockwell hardness tester can be used to test the HRN hardness value.