Mathematical Simulation and Experimental Verification of Carburizing Quenching Process Based on Multi-Field Coupling

Jiangang Wang,Xusheng Li,Yong Chen,Jianhui Li,Shuai Yang,Fangbo He,Hui Li,Dongying Ju

doi:10.3390/coatings11091132

Abstract

Based on the multi-field coupling effect of temperature, diffusion, and phase change, the finite element model of carburizing and quenching was established. The 20CrMnTiH steel helical gear as the research object, prediction accuracy of carburizing, and quenching model of complex helical gear was studied. The material properties database of experimental steel was established by JMatPro, and the material thermophysical parameters needed in the calculation process were obtained. The carburizing and quenching process of transmission helical gear was numerically simulated by thermodynamic three-dimensional coupling analysis method combined with actual heat treatment process. The microstructure morphology, macro hardness, and deformation were characterized. The experimental results show that the microstructure of the hardened surface layer was acicular martensite and a small amount of residual austenite. The highest hardness appears at the surface layer of 778.8 HV, the effective hardened layer depth was 0.9 mm, and the maximum deformation of the gear was 0.055 mm. By comparing the experimental measurement results with the simulation results, they were in good agreement, which verifies the accuracy of the finite element model. This indicates that the model has good prediction ability in carburizing and quenching process.

Highlights

With the rapid development of the new energy automobile industry, higher requirements are put forward for the performance of the key parts of the transmission system, especially the surface hardness and wear resistance
The resulting excessive residual stress, deformation, and cracking are the most important issues affecting the performance of gear products
Based on the theory metalofthermodynamics, the carburizing and quenching process processgear of helical gear was studied byan combining an with experiment with numericalFrom simulation

Summary

Introduction

With the rapid development of the new energy automobile industry, higher requirements are put forward for the performance of the key parts of the transmission system, especially the surface hardness and wear resistance. Surface strengthening process (carburizing and quenching) is the key technology for reliable performance of the gear [1], which is an important factor directly affecting the performance. The surface layer will generate a martensite structure with high hardness and good wear resistance. In this process, the gear bears complex boundary conditions such as heat and diffusion, and the generated stress is complex and changeable [5,6,7]. The resulting excessive residual stress, deformation, and cracking are the most important issues affecting the performance of gear products

Methods

Results

Conclusion