Effects of Steel and Tungsten Carbide Ball Indenters on Rockwell Hardness Measurements

Abstract The Rockwell hardness (HR) test is a valuable and widely used indentation hardness test for evaluating mechanical properties of metallic materials. For the Rockwell scales that use a ball indenter, either a steel or tungsten carbide (WC) ball indenter is permitted to be used in the current standards of ASTM International and the International Organization for Standardization. However, significant differences occur in Rockwell hardness tests depending on whether the ball indenter that is used is made of steel or WC. In this paper, finite element analysis is used to simulate the HR indentation process using steel and WC ball indenters on the same test materials under the same testing conditions. The effects of four different sizes of steel and WC ball indenters on different Rockwell hardness scales are studied and compared with the experimental tests. This study provides important approximations of differences between the performance of steel and WC Rockwell hardness indenters.