Surface roughness requirements in mobile hardness testing of metallic materials

摘要

The impact of the surface roughness and the number of measurements on the reliability and variance of the results of mobile hardness testing of metallic materials are critically investigated. For this purpose, the most frequent techniques, namely UCI, Leeb und TIV, are applied to four different common steels of controlled roughness. As the mobile techniques usually lack a visual control of the indentation, the reliability of the results has to be established by the dispersion of the single values. However, it is shown that the roughness results are often below the limitations of international standards under the given conditions. Moreover, the number of single measurements should be raised sufficiently, especially in cases of elevated roughness levels.