An optimized hardness model for carburizing-quenching of low carbon alloy steel

• Published in: Journal of Central South University Vol. 24; no. 1; pp. 9 - 16
• Main Authors: Zhang, Xing, Tang, Jin-yuan, Zhang, Xue-rui
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.01.2017; Springer Nature B.V
• Subjects: Alloy steels; Carbon content; Carburizing; Engineering; Hardness; Low carbon steels; Martensite; Metallic Materials; Phase transitions; Quenching; Retained austenite; Simulation models; Temperature distribution; high carbon content; hardness model; DEFORM-HT; residual austenite; carburizing-quenching simulation
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-017-3403-2

Research has been conducted about the hardness prediction for the carburizing and quenching process based on an optimized hardness simulation model, in accordance with the calculation rule of mixed phases. The coupling field model incorporates carburizing field analysis, temperature field analysis, phase transformation kinetics analysis and a modified hardness calculation model. In determination of the calculation model for hardness, calculation equations are given to be applied to low carbon content ( x (C)≤0.5%) for the child phases and the martensite hardness is calculated for high carbon content ( x (C)>0.5%) in alloy. Then, the complete carburizing-quenching hardness calculation model is built, and the hardness simulation data are corrected considering the influence of residual austenite (RA) on hardness. Hardness simulations of the carburizing and quenching process of 17CrNiMo6 samples have been performed using DEFORM-HT_V10.2 and MATLAB R2013a. Finally, a series of comparisons of simulation results and measured values show a good agreement between them, which validates the accuracy of the proposed mathematical model.