摘要
研究火车车钩用钢ZG25MnCrNiMo经过不同调质工艺处理后-40℃的冲击性能。分别用金相显微镜、扫描电镜和透射电子显微镜观察和分析钢的微观组织、低温冲击断口形貌和钢中碳化物的析出行为。结果表明,ZG25MnCrNiMo钢在910℃淬火、550℃回火2 h得到均匀回火索氏体组织,冲击功最大。冲击功随回火温度的升高而增大。低于550℃回火,钢中的碳化物主要在板条界面呈连续析出,-40℃冲击功低;550~650℃回火,铁素体呈等轴状且碳化物分布于晶内,表现出高的冲击性能。
Impact property at-40 ℃ of ZG25MnCrNiMo steel used for railcar coupler after different quenching and tempering processes was explored.The microstructure,fracture surface of low-temperature impact specimens and precipitation behavior of carbides in the steel were characterized by optical microscope,SEM and TEM respectively.The results show that homogeneous tempered sorbite in the steel is obtained by quenching at 910 ℃ and tempering at 550 ℃ for 2 h,and exhibits the maximum impact energy.The impact energy increases with increasing the tempering temperature.Carbides in the steel are precipitated along the lath interface tempered under lower than 550 ℃,and the impact energy at-40 ℃ is poor.Equiaxed ferrite and carbides distributed in the grains of the steel are observed when the tempering temperature is 550-650 ℃,which produces better impact property.
出处
《金属热处理》
CAS
CSCD
北大核心
2010年第7期1-4,共4页
Heat Treatment of Metals
