GCr15钢滚动轴承疲劳剥落失效过程中一种针状相的形成  

Formation of a Needle-Like Structure when Surface Flaking Occurs During the Rolling Contact Fatigue of a GCr15 Bearing

作　　者：程胜 孙阳 赵文辉[3] 栾义坤[1,2] 郑成武 李殿中[1] CHENG Sheng;SUN Yang;ZHAO Wenhui;LUAN Yikun;ZHENG Chengwu;LI Dianzhong(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;School of Mechanical Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]中国科学院金属研究所沈阳材料科学国家研究中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016 [3]沈阳工业大学机械工程学院,沈阳110870

出　　处：《金属学报》2024年第4期425-433,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.52031013;中国科学院战略性先导科技专项项目No.XDC04040203。

摘　　要：在发生表面剥落的GCr15钢滚动轴承的表面裂纹附近发现了一种针状相,利用SEM、透射Kikuchi衍射(TKD)和TEM等表征手段研究了这种针状相的微观特征,分析了这种针状相的形成机理及其与表面裂纹的相互作用。结果表明,在GCr15钢滚动轴承表面诱发的裂纹附近所形成的针状相是一种特殊的马氏体退化组织。这种针状相是因局部应力作用而形成的细长条状组织,其三维形貌为薄板状,内部存在微观孔洞和等轴状纳米晶。在滚动接触疲劳过程中,表面裂纹会优先沿针状相的微观孔洞扩展,使针状相的形成与表面裂纹的扩展相互促进,加速了轴承表面疲劳剥落的发生。As a form of damage caused by rolling contact,rolling contact fatigue(RCF)can lead to early pitting and flaking on the raceway surface of bearings,which is frequently accompanied by the propagation and fracture of RCF cracks.When the RCF crack is initiated on the raceway surface,large amount of stress,e.g.,fluid pressurization,may be exerted close to the crack faces,which can not only accelerate the crack growth and cause rapid failure of the bearing but also lead to local microstructural alternations in the bearing steel.In this study,a needle-like structure was observed close to the cracks with flaking occurring during RCF in a GCr15 rolling bearing.The microstructures of the needle-like structure were analyzed via SEM,transmission Kikuchi diffraction(TKD),and TEM to elucidate its microstructural constitutions and characteristics.Results illustrated that the needle-like structure is a thin plate in three dimension decorated with some microvoids and equiaxed ferrite nanocrystalline formed at the interfaces.The formation of the needle-like structure was attributed to the local stress exerted close to the crack surface during the RCF of the bearings.This structure may be a type of decayed microstructure of the martensitic matrix of the bearing steel.With the increasing RCF stress cycles,the microvoids in the needlelike structure may facilitate the initiation and propagation of surface cracks preferentially,thus accelerating the occurrence of surface fatigue flaking in the bearing.

关 键 词：GCR15钢 滚动接触疲劳 表面裂纹 针状相 

分 类 号：TG142[一般工业技术—材料科学与工程]