钴和钼对高钴铬钼轴承钢组织及力学性能影响

发布时间：2019-03-29 15:21

【摘要】：通过性能测试和组织观察,研究了钴和钼两种元素对高钴铬钼轴承钢组织和力学性能的影响规律。结果表明,钴和钼元素质量分数降低及匹配改变会使试验钢的综合力学性能降低。试验钢的淬火及回火组织为板条马氏体+残余奥氏体,在钴和钼元素的影响下,Cr_(eq)、Ni_(eq)差值变大,致使试验钢组织中残余奥氏体减少,产生δ-铁素体。并且,碳化物由质量分数1.17%的颗粒状M6C改变成质量分数低于0.15%的针状M_2C。试验钢的强度主要受碳化物影响,而在碳化物质量分数低于0.15%时,w(Co)/w(Mo)的值越小,位错密度越高,则试验钢的强度越高。试验钢的韧性主要受δ-铁素体影响,δ-铁素体面积分数大于6.3%,则试验钢会产生脆性,面积分数小于1.1%则试验钢的韧性较好。
[Abstract]:The effects of cobalt and molybdenum on the microstructure and mechanical properties of high cobalt chromium molybdenum bearing steel were studied by means of properties test and microstructure observation. The results show that the comprehensive mechanical properties of the tested steel can be reduced by decreasing the mass fraction of cobalt and molybdenum and changing the matching. The quenched and tempered microstructure of the test steel is lath martensitic retained austenite. Under the influence of cobalt and molybdenum elements, the difference of Cr_ (eq), Ni_ (eq) increases, resulting in the reduction of retained austenite and the formation of 未-ferrite in the microstructure of the tested steel. In addition, carbides change from 1.17% granular M6C to less than 0.15% acicular M2C. The strength of the tested steel is mainly influenced by carbides. When the mass fraction of carbides is less than 0.15%, the smaller the value of, w (Co) / w (Mo) and the higher the dislocation density, the higher the strength of the tested steel. The toughness of the tested steel is mainly affected by 未-ferrite. If the area fraction of 未-ferrite is more than 6.3%, the test steel will produce brittleness, and the toughness of the tested steel is better if the area fraction is less than 1.1%.
【作者单位】：昆明理工大学材料科学与工程学院;钢铁研究总院特殊钢研究所;
【基金】：国家高技术研究发展(863)计划资助项目(201203A503)
【分类号】：TG142.1

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