JOHNSON COOK CONSTITUTIVE MODELING FOR AUSTENITE METAL IN HOT FORMING PROCESS

Abstract

Numerical computations have helped process engineers in designing the stamping process with minimal process defects. The constitutive modelling for hot stamping represents a complex relationship between stress, strain, strain rate and process temperature. The sheet thickness is 1.5 mm were prepared according to the ASTM standard. The flow curve properties of NPH-1500 sheet were investigated by conducting uniaxial tension tests with temperature from 600oC to 800oC and subjected to strain rate of 0.1/s,1/s and 10/s. The flow curves for the respective experiment runs were investigated and modelled with Johnson Cook constitutive modelling where the important metal parameters were derived. Based on the results, the error of the metal parameters values from experimental works and commercial database was found to be less than 5%.