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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。
The influence of cobalt and molybdenum on the microstructure and mechanical properties of high cobalt-molybdenum-molybdenum bearing steel was studied by performance test and microstructure observation. The results show that the decrease of the mass fraction of cobalt and molybdenum and the change of the matching result in the decrease of the comprehensive mechanical properties of the test steel. Under the influence of cobalt and molybdenum, the difference of Cr_ (eq) and Ni_ (eq) became larger, which resulted in the residual austenite in the test steel. The quenched and tempered microstructure of the test steel was lath martensite + retained austenite. Decreased body, resulting in δ-ferrite. In addition, carbide was changed from 1.17% by mass of granular M6C to acicular M_2C with mass fraction of less than 0.15%. The strength of the test steel is mainly affected by carbides. When the mass fraction of carbides is less than 0.15%, the value of w (Co) / w (Mo) is smaller and the dislocation density is higher, the strength of the test steel is higher. The toughness of the test steel is mainly affected by δ-ferrite. When the δ-ferrite area fraction is more than 6.3%, the test steel will have brittleness, and the test steel has better toughness when the area fraction is less than 1.1%.