Affiliation:
1. Aero Engine Corporation of China, Beijing 100097, China
2. Institute for Aero Engine, Tsinghua University, Beijing 100084, China
Abstract
Using nanoindentation technology to analyze the hardness and elastic modulus distributions of the local microzones within materials, it can be determined that the case-carburized specimen is a composite of the carburized case and the pseudo-carburized material in the core. The overall mechanical behavior of the case-carburized material is much closer to that of the completely carburized material, indicating that the carburized case dominates the case-carburized material. Stress fatigue tests conducted on carburized tubular specimens, pseudo-carburized solid specimens, and case-carburized solid specimens showed that the fatigue performance of the completely carburized material is slightly lower than that of the pseudo-carburized specimens due to lower plasticity. However, the fatigue performance of the case-carburized specimens is significantly better than that of the two homogeneous materials. This could be attributed to the graded material behavior and the larger compressive residual stress in the carburized case, which are the primary positive factors for improving the fatigue life of case-carburized materials. SEM fractographs revealed that the fatigue nucleation in the case-carburized specimen initiates from the transition zone rather than from the surface of the specimens as observed in the homogeneous materials. Low-cycle fatigue evaluation of ultra-high-power gear transmission systems should focus on the influences of the carburized case.
Funder
Aerospace Power Foundation of China
Subject
Process Chemistry and Technology,Chemical Engineering (miscellaneous),Bioengineering
Reference25 articles.
1. Increasing the bending fatigue strength of carburized spur gear teeth by presetting;Woods;Int. J. Fatigue,1999
2. The Heat Treatment Technique in Gear Manufacturing of China;Min;Heat Treat. Met.,2005
3. Stickels, C.A. (1992). Carburizing, Friction, Lubrication, and Wear Technology, ASM Handbook, ASM International.
4. Cyclic deformation and fatigue behavior of carburized automotive gear steel and predictions including multiaxial stress states;Bonglae;Int. J. Fatigue,2017
5. Effect of Residual Stress on Fatigue Failure of Carburized Low- Carbon Steel;Kanchanomai;J. Mater. Eng. Perform.,2008