한국표면공학회지 (45권6호 226-231)
Characteristics of Carburized Surface Layers in 0.18C-3.5Ni-1.5Cr-0.2Mo Steels for Main Shaft Bearings of Wind Turbines
풍력발전시스템의 주 베어링용 0.18C-3.5Ni-1.5Cr-0.2Mo강의 침탄 표면특성
최병영;구윤식;
Choi, Byung-Young;Gub, Yoon-Sik;
전북대학교 신소재공학부 및 신소재개발연구센터;전북대학교 대학원 금속공학과;
School of Advanced Materials Engineering and Research Institute of Advanced Materials Development, Chonbuk National University;Graduate School of Metallurgical Engineering, Chonbuk National University;
Characteristics of carburized surface layers in 0.18C-3.5Ni-1.5Cr-0.2Mo steels for main shaft bearings of wind turbines have been analyzed and evaluated before and after rolling contact fatigue tests. Mixed microstructure consisting of retained austenite and tempered martensite has been formed with compressive residual stresses in the surface hardened layers of the specimens showing uniform hardness distribution with value about Hv700 after vacuum carburizing and tempering. It has been found on the raceway of the layers of the specimens after rolling contact fatigue tests that the amount of retained austenite decreased and compressive residual stresses increased, resulting from cyclic contact stresses applied during the tests. It has been also revealed that higher durability of the bearings can be obtained through controlling the amount of the retained austenite in the surface of the bearing steels to be lower in this study.
0.18C-3.5Ni-1.5Cr-0.2Mo steels;Surface hardened layer;Retained austenite;Cyclic contact stresses;Durability;
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