A Study on the Ball Indentation Test for Linear Hardening Metals

In this work, a numerical analysis based on the linear hardening model and ball indentation test was proposed to determine the properties of materials such as austenitic stainless steels that obey linear hardening behavior. Experiments on 304 and 321 austenitic stainless steel showed that the numerical method provides yield and tensile strength values with a maximum error of less than 5% and the hardening behavior identical with uniaxial tensile tests, while the average error for yield strength was more than 30% with the empirical method. The reasons why the empirical method produces larger errors for non-power law materials were analyzed in detail. The elastic modulus calculation method was also re-investigated, and the model based on re-loading showed much bigger equivalent contact diameters and provided more accurate elastic modulus values in a simple way.