【摘要】 研究了淬火温度对马氏体合金钢性能和显微组织的影响。采用不同的淬火温度进行热处理,测量了硬度和室温冲击韧性,在光学显微镜、SEM和TEM下观察了显微组织,利用EBSD技术采集了晶粒取向分布并用Channel 5软件分析了晶界特征,实验结果表明:随着淬火温度的增加,硬度和室温冲击韧性都呈现先上升后下降的规律,在900℃淬火达到强韧性最佳组合,硬度达39 HRC,室温冲击吸收功66 J。在奥氏体晶粒不发生长大,析出物形态、分布无显著差异的情况下,钢的强韧性增加的主要原因为马氏体组织中特征晶界数量的增加。更多还原

【Abstract】 Effects of quenching temperature on mechanical properties and microstructure of a low-carbon steel were investigated.Samples were austenitized at different temperatures and oil quenched.Tempering was carried out at 200 ℃ for 2 h.Hardness and impact energy were determined for the steel under all heat treatment conditions.The microstructure was characterized by OM,SEM and TEM.EBSD and software Channel 5 were used in collection of grain orientation distribution and analysis of grain boundary characters,respectively.The results show that the steel exhibites peak hardness of 39 HRC and impact energy of 66 J when quenching at 900 ℃ and tempering at 200℃.Under the condition that the austenitic grains do not grow up and precipitates have no significant difference in the morphology or distribution,the main reason for ductile improvement is the increasing quantity of boundaries in the martensite structure.更多还原