Empirical model predicting the value of the strain-hardening exponent of a Ti-IF steel grade

摘要

The article aims at studying the influence of a Ti-IF steel grade microstructure on the strain-hardening exponent and establishing an empirical formula that could be used to predict its value as a function of the microstructural parameters. For that, some materials with different grain sizes and/or precipitation states were prepared by controlling the thermomechanical processing parameters. Based on uniaxial tensile tests carried out at 2 x 10~(-3) s~(-1) and at room temperature, a simple linear relationship between the measured strain-hardening exponent n and the yield strength value, YS, is found. This is the basis of the empirical model established from the foregoing property using physically meaningful models present in literature, which permits calculation of all the hardening contributions to the yield strength, and a thorough experimental characterization of the studied steel grade microstructure. Finally, the calculated values of n are presented and discussed for the studied Ti-IF steel grade.