Abstract: Through the standard detection and rating the metallurgical quality of the high clean bearing steel prepared by vacuum degassing process， such as chemical composition， macrostructure， carbide inhomogeneity and non-metallic inclusions， and quantitative analysis of the quantity， type， size and cleanliness index of non-metallic inclusions in the steel is carried out by Aspex scanning analyzer. Based on the rolling contact fatigue life test results， the relationship between non-metallic inclusions and bearing steel contact fatigue life was established. The results show that the oxygen content of high clean bearing steel is not more than 0.000 5%， the titanium content is not more than 0.000 8% and the large particle inclusions DS is not more than 0.5， however it is still a contact fatigue failure mechanism dominated by inclusions， among which the size of oxide inclusions are large and there are holes around the inclusions， which is easy to cause stress concentration and fatigue cracks. The maximum size of oxide inclusions in high clean bearing steel is controlled below 10 μm， and the rated life L10 under 4.5 GPa high contact stress is more than 1×107 times， which is expected to replace electroslag remelting bearing steel for high-speed rail， high-speed machine tool spindle， wind power spindle and other high-end equipment fields.

Key words: High Clean Bearing Steel GCr15, Nonmetallic Inclusion, Rolling Contact Fatigue, Failure Mechanism, High-end Equipment

摘要： 通过对真空脱气工艺制备的高洁净轴承钢的化学成分、低倍组织、碳化物不均匀性、非金属夹杂物等冶金质量进行标准检测及评级，并利用Aspex扫描分析仪对钢中的非金属夹杂物的数量、类型、尺寸及洁净度指数等进行定量分析，结合滚动接触疲劳寿命试验结果，建立了非金属夹杂物与轴承钢接触疲劳寿命的关系。研究结果表明，高洁净轴承钢的w［O］≤0.000 5%，w［Ti］≤0.000 8%，大颗粒夹杂物DS≤0.5级，但仍是以夹杂物为主导的接触疲劳破坏机制，其中，氧化物类夹杂尺寸较大，并在夹杂物周围存在孔洞缺陷，易于造成应力集中形成疲劳裂纹。高洁净轴承钢中氧化物类夹杂的最大尺寸控制在10 μm以下，4.5 GPa高接触应力下的额定寿命L10达到1×107次以上，有望取代电渣重熔轴承钢用于高铁、高速机床主轴、风电主轴等高端装备领域。

关键词: 高洁净轴承钢GCr15, 非金属夹杂物, 滚动接触疲劳寿命, 破坏机制, 高端装备