To deeply investigate the effect of rare earth(La/Ce)on inclusions and fatigue properties of 20CrMnTi gear steel,the inclusions in 20CrMnTi and 20CrMnTi-RE gear steel treated with 0.002 7% rare earth were analyzed and characterized by various analytical and testing methods,the change of fatigue property was compared and analyzed.The ultra-high weekly fatigue test was carried out and analyzed the change of fatigue properties.The results show that rare earth can react with O element in gear steel to form rare earth oxides,and co-exist with other inclusions such as CaS and MgAl2O4,which become the core of TiN,the complex phase of CaS-MgAl2O4-(MnS)-TiN is transformed into the complex phase of CaS-MgAl2O4-(MnS)-RE2O3-TiN.After addition of rare earth,the amount of inclusions in 20CrMnTi steel decreased significantly,and the inclusions with size over 30 µm basically disappeared.In addition,rare earth improves the anti-fatigue property of gear steel.The fatigue limit of gear steel with rare earth is 26.6 MPa higher than that of gear steel without rare earth at the condition of 50% failure probability for 107 cycles,with better anti-fatigue performance.
关键词
20CrMnTi齿轮钢/稀土/夹杂物变性/疲劳性能
Key words
20CrMnTi Gear Steel/Rare Earth/Denaturation of Inclusions/Fatigue Property
维普
万方数据