구름 접촉 피로 시험을 통한 M50소재의 피로 거동 및 마모 거동 분석

This study evaluates the fatigue characteristics of aerospace-grade M50 steel through rolling contact fatigue (RCF) testing, simulating the extreme operating conditions of gas turbine engine bearings to predict the material performance and fatigue life. Actual bearing operating conditions have been replicated to investigate the fatigue and wear behavior, thus enabling an assessment of the reliability and durability of the material and predicting its optimal application based on RCF test results. Tests have been conducted under two different conditions of contact load, and the wear and failure mechanisms have been analyzed through failure time measurements and post-test surface observations. The results show that under low-contact pressure, fatigue life increases because of gradual wear and subsurface fatigue. Conversely, at high-contact pressure, fatigue life is significantly reduced, with surface fatigue and spalling being identified as the primary wear mechanisms. SEM analysis after RCF testing reveals irregular wear surfaces and unpredictable failure patterns, including surface cracks and spalling. The findings highlight the significant influence of contact load on the fatigue performance and wear behavior of M50 steel in ball bearings and provide essential baseline data for its application in gas turbine engine bearings. Moreover, this study enhances the understanding of the fatigue and wear behavior under extreme conditions of M50 steel contributing to the selection of optimal materials and the development of improved maintenance strategies for high-performance rotating systems.