【摘要】 采用扫描电镜、能谱分析、力学性能测试等方法研究NM450耐磨钢经过860℃、880℃、900℃、920℃不同温度二次淬火后力学性能、微观组织和耐磨性能的变化规律。结果表明：880℃二次淬火得到的试样晶粒平均尺寸最小，900℃一次淬火组织中的细长马氏体板条转变为短粗状马氏体板条，试样硬度、强度最高。通过6 000次三体冲击磨损试验，发现900℃一次淬火NM450钢的磨损表面为犁沟、微切削及疲劳损伤，880℃二次淬火NM450钢的磨损表面为鳞剥与疲劳损伤。二次淬火能有效提高NM450钢的耐磨性能，经880℃二次淬火的试样磨损量最小，耐磨性能最好。更多还原

【Abstract】 The changing law for the mechanical properties, microstructure and wear resistance of NM450 wear-resistant steel with different secondary quenching temperatures of 860 ℃,880 ℃,900 ℃,920 ℃ are studied by means of scanning electron microscopy(SEM),energy spectrum analysis and mechanical test.The result shows that the average grain size of the samples obtained by secondary quenching at 880 ℃ is the smallest.The microstructure is transformed from slender martensite lath in primary quenching at 900 ℃ to stubby martensite lath in secondary quenching, the sample has the highest hardness and the strength.After 6 000 times of three-body impact wear test, it is found that the wear surface of NM450 steel with primary quenching at 900 ℃ is furrow, micro-cutting and fatigue damage, the wear surface of NM450 steel with secondary quenching at 800 ℃ is scale exfoliation and fatigue damage.Secondary quenching can effectively improve the wear resistance of NM450 steel.The sample after secondary quenching at 880 ℃ has the least wear and the best wear resistance.更多还原