Hardness Test of Welded Parts

Welding is an indispensable common basic technology in the manufacturing industry. Since the formation process of the welded joint (weld) involves heat, stress and microstructural changes, it often becomes a weak link in the welded structure. Especially when there is a brittle hard phase (such as twin martensite) in the weld, it will reduce the ductility and toughness of the welded joint, and it is easy to cause embrittlement and fracture.

For this reason, the hardness of the weld often becomes an important basis for judging whether the welding process is reasonable. Hardness can not only measure the hardness of the material, but also sensitively reflect the differences in chemical composition, microstructure, hot processing technology and cold processing deformation of metal materials. Therefore, it is also widely used in welding material detection and failure analysis.

Welding hardness test is one of the important means to measure the quality and effect of welding joints. Commonly used test methods mainly include the following three:

1. Brinell hardness test method. This is a commonly used non-destructive test method. The quality of the welded joint can be evaluated by measuring the hardness value of the surface of the welded joint using a hardness tester. Commonly used Brinell hardness testers are rock hardness testers and metal hardness testers. The specific choice should depend on actual needs.

2. Rockwell hardness test method. This test method also uses a hardness tester to measure the hardness value of the welded joint surface. Compared with the Brinell hardness test method, it has a wider range of hardness grades and can perform more accurate measurements. However, it is relatively cumbersome because it requires special processing of the sample and must meet certain standard requirements.

3. Vickers hardness test method. This test method is mainly suitable for measuring the hardness of welding materials. It can perform macroscopic observation of welding nodes and conduct quality assessment. It is simple and convenient to operate and does not require heat treatment.

Fully Automatic Superficial Twin Rockwell Hardness Tester IQUALITROL 420HRSS-150Z

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