Weld Seam Hardness Testing
Hardness testing of a weld checks the hardness of a weld to detect hardening and ensure quality.
Physical-Chemical Mechanism of Action
Hardness of a material sample is determined by measuring the force required to cause a specific indentation in the sample. For weld samples, this can be done using various methods such as the Brinell test or the Rockwell hardness test.
Metallurgical Relevance & Welding Risks
Hardening can occur in weld areas when the material cools too quickly. This leads to excessive hardness and increases the risk of cracks and fractures. A test weld hardness test can detect these hardenings and ensure weld quality.
Workshop Practice & Action Instructions
For a correct test weld hardness test, it is important that the sample is representative of the entire weld. Hardness measurement should be done near the heat-affected zone. In a Brinell test, a specific depth and width of the indentation is measured to determine hardness. In a Rockwell hardness test, a heavy cone is pressed into the sample, and the depth of the indentation is measured. Results should fall within an acceptable hardness range specified for the specific material and application.