Maraging steel phase transformation in high strain rate grinding

In this paper, the modeling of material phase transformation in grinding processes by examining strain rate and contact zone temperature to quantitatively link to the kinetics of diffusion-controlled as well as diffusionless transformations is presented. Based upon the addition of volume fractions in sequential segmented isothermal processes characteristic to grindings, physics-based modeling and prediction for the volume fraction of phase transformation in continuous heating under anisothermal conditions are developed. In validation of the predictive model, a series of maraging steel 250 grinding experiments, XRD measurements, and regression analyses were pursued. The comparison of experimental resulting data and the model prediction of volume fraction of austenite, martensite, and ferrite phases after grinding have been done. It is seen that the physics-based model presents the practicability to predict the incidence and extent of phase transformation as related to material properties, wheel characteristics, and grinding thermal-mechanical loadings.