Experimental determination of sensitivity coefficients of some influence parameters in Rockwell B, C, 15N, 30N and 45N

The impact of key variables on hardness measurements, including indenter velocity, geometry, dwell times, forces, and temperature, has been extensively studied in recent decades. The recent adoption of international Rockwell hardness scale definitions has intensified this interest. While these definitions and relevant standards consider parameter ranges, the Rockwell hardness equation lacks explicit incorporation of these variables, requiring an empirical determination of their sensitivity coefficients. This study focuses on the determination of sensitivity coefficients associated with two main influential parameters − the velocity of the final load application and the time interval for the force variation from the preliminary force value to the total force value − across Rockwell B, C, 45N, 30N, and 15N hardness scales at various hardness levels, using a Monte Carlo method and multiple linear regression. The results align with findings in existing literature, enhancing the robustness and reliability of the study.