Test Sample Surface Finish
The surface quality of test specimens refers to their roughness and parallelism before hardness testing. A bad condition leads to inaccurate measurement values.
Physical-Chemical Mechanism of Action
The surface quality of test samples concerns their roughness and flatness. High roughness can affect light diffraction, while uneven surfaces distort measurement accuracy in optical evaluation.
Metallurgical Relevance & Welding Risks
Poor surface quality leads to inaccurate hardness readings. This can cause errors in strength assessment and misclassification of the steel, leading to safety issues in the workshop.
Workshop Practice & Action Instructions
Ensure test samples are smooth and flat. Use high-quality materials for surface preparation and avoid over-finishing, as this can cause uneven surfaces. A roughness of max. 0.4 µm is typical for accurate hardness testing.