各类型夹杂物对轴承钢疲劳失效的作用与评价  

Contribution of different types of inclusions to fatigue failure of bearing steel and quantitative evaluations

作　　者：陈峰[1] 汪峥 童忆 罗海文[1] CHEN Feng;WANG Zheng;TONG Yi;LUO Haiwen(School of Metallurgy and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Daye Special Steel Co.,Ltd.,Huangshi 435000,Hubei,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]大冶特殊钢股份有限公司,湖北黄石435000

出　　处：《中国冶金》2024年第9期103-112,共10页China Metallurgy

基　　金：国家自然科学基金资助项目(52233018,51831002)。

摘　　要：夹杂物是影响轴承钢疲劳性能的重要因素。以国产超洁净GCr15轴承钢为研究对象,通过ASPEX扫描电镜对钢中氧化夹杂物、氧硫复合夹杂物、硫化夹杂物及TiN夹杂物4类夹杂物进行检测统计,并使用极值分析方法中的极值(SEV)法和广义Pareto分布(GPD)法分别预测钢中这4类夹杂物的最大特征尺寸;另外,通过旋转弯曲疲劳试验来发现引起疲劳失效的夹杂物。将这2类方法所得结果进行对比分析,发现氧硫复合夹杂物引起的疲劳失效最多,且通过旋转弯曲试验检测到的引起疲劳裂纹的该夹杂物最大尺寸与GPD法的预测值更接近;虽然硫化夹杂物尺寸最大、数量最多,但未在疲劳断口上观察到,说明单一硫化物对疲劳断裂的危害最小;尽管TiN夹杂物数量稀少,但是依然可观察到其导致的疲劳失效,说明TiN对疲劳性能的危害很大;未观察到氧化夹杂物引起的疲劳失效,且检测到的氧化夹杂物最大尺寸约为10.7μm、GPD法预测的最大特征尺寸约为12.4μm,这说明单一氧化夹杂物不具有疲劳危害性的临界尺寸可能为10.7~12.4μm。研究结果为GCr15轴承钢疲劳性能的改善提供了理论指导。Inclusion is an important factor affecting the fatigue properties of bearing steel. Taking an ultraclean GCr15(100Cr6) bearing steel produced in China as the research object, four types of inclusions in the steel were investigated and statistically analyzed, including oxide, oxide-sulfide, sulfide, and TiN using the ASPEX scanning electron microscope. The maximum characteristic size of each type of inclusions in the steel was predicted separately using the methods Statistical Extreme Value (SEV) and the Generalized Pareto Distribution (GPD). In addition, inclusions causing fatigue failure were found by rotating bending fatigue test. Comparative analysis of the results obtained from these two approaches shows that the most frequent fatigue failure is caused by oxide-sulfide inclusions, and the maximum size of this type of inclusions measured on the fatigue fracture is closer to that predicted by the GPD method. Although there are the largest number of sulfide with the coarsest size in the ultraclean bearing steel, they do not induce the fatigue fracture at all, indicating that they are the least harmful to fatigue failure. There are very few large TiN inclusions in the steel, but TiN-induced fatigue crack is indeed observed, indicating that TiN inclusions are detrimental to fatigue properties even though they are few. No oxide inclusions are found on the fatigue fracture and the measured oxide inclusions have the largest size of 10.7 μm and the predicted maximum size by GPD is 12.4 μm, suggesting that the critical size of the oxide inclusion not to induce fatigue cracking is probably between 10.7 μm and 12.4 μm. The results of the study provide theoretical guidance for the improvement of the fatigue properties of GCr15 bearing steel.

关 键 词：GCR15轴承钢 ASPEX 夹杂物 统计极值法 广义Pareto分布法 旋转弯曲疲劳试验 

分 类 号：TG142.1[一般工业技术—材料科学与工程]