Rebound hardness testing
The rebound hardness test measures the hardness of a material by measuring the rebound velocity of a striking body. It enables non-destructive hardness determination on large, assembled components.
Physicochemical Mechanism of Action
A rebound hammer is struck against the material surface with a defined energy. The rebound velocity is measured and converted into a hardness value. The harder the material, the slower the rebound.
Metallurgical Relevance & Welding Risks
Rebound hardness indicates how hard the surface of a material is. If hardness is too high, the material may crack under mechanical stress. Too low hardness can lead to wear and corrosion. It is important to maintain optimal hardness in the weld zone to ensure a sound joint.
Workshop Practice & Procedures
Use a rebound hardness tester with a defined mass and velocity. Ensure the impact is perpendicular to the surface. Measurements should be taken with a calibrated instrument. A hardness of 40-50 HRC (Rockwell C) is typical for many metals. If results are unsatisfactory, check welding parameters and the material.