The uncontrolled distortion of steel parts has been a long-standing and serious problem for heat treatment processes, especially quenching. To get a better understanding of distortion, the relationship between transformation kinetics and associated distortion has been investigated using a low-alloy chromium steel. Because martensite is a major phase transformed during the quenching of steel parts and is influential in the distortion, a new martensite start (Ms) temperature and a martensite kinetics equation are proposed. Oil quenching experiments with an asymmetrically cut cylinder were conducted to confirm the effect of phase transformations on distortion. ABAQUS and its user-defined subroutines UMAT and UMATHT were used for finite element method (FEM) analysis. The predictions of the FEM simulation compare well with the measured data. The simulation results allow for a clear understanding of the relationship between the transformation kinetics and distortion.
Bibliographical noteFunding Information:
This research was supported by the National Core Research Center (NCRC) program from MOST and KOSEF (No. R15-2006-022-01002-0). The authors are grateful to Professor C.J. Van Tyne at the Colorado School of Mines for helpful discussions.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys