indentation hardness
Universal hardness is a combined hardness value that takes into account both plastic and elastic deformation. It's determined from force-displacement curves and gives a more complete picture of material behavior under load.
Physical-Chemical Mechanism of Action
Universal hardness measures the overall hardness of a material through a combination of plastic and elastic deformation. It is determined by analyzing the force-displacement curve, considering both the maximum force moment and the total strain.
Metallurgical Relevance & Risks During Welding
Universal hardness is especially important for materials with complex microstructures or under high loads. Too high hardness can lead to crack-sensitive microstructures, while too low hardness can lead to plastic deformation and possible failure. During welding, it is crucial that the material remains stable in its universal hardness to ensure the lifespan and safety of components.
Workshop Practice & Actions
To determine the universal hardness of a material, a specific force-displacement curve is measured. This requires precise measuring instruments and correct load application. During welding, it is important that the material is not welded beyond its hardness capabilities. This can be ensured by selecting the right welding process and controlling process parameters (temperature, time, voltage).