本文研究了65Mn钢马氏体/下贝氏体复相组织的室温韧性和磨料磨损性能随下贝氏体量的变化。下贝氏体量<25%时,耐磨性不低于常规淬火组织,而韧性明显改善。定量金相测定表明贝氏体分割奥氏体区使马氏体领域细化,是复相组织强韧化的主要原因。扫描断口分析证实断裂单元与贝氏体的平均间距相吻合。 In this paper, the room temperature toughness and abrasive wear properties of martensitic / lower bainitic composite microstructure of 65Mn steel were studied with the changes of lower bainite. When the lower bainite content is less than 25%, the wear resistance is not less than the conventional quenched structure, but the toughness is obviously improved. Quantitative metallographic examination shows that the division of austenitic bainite martensite area refinement is the main reason for the complex phase toughness. Scanning fracture analysis confirmed the fracture unit consistent with the average spacing of bainite.