【摘要】 对淬火后H13钢进行620,640,660,680℃下保温10,20,40min的预回火与600℃保温120min回火处理，并以常规回火（二次600℃保温120min回火）为对照，研究了预回火工艺对H13钢组织和性能的影响。结果表明：随着预回火温度提高或保温时间延长，H13钢中马氏体分解程度增加，残余奥氏体数量减少，析出碳化物尺寸增大，位错密度降低，H13钢的硬度降低，冲击吸收功增大；与常规回火相比，620,640℃下预回火10～20min+600℃回火后H13钢的位错密度更高，660,680℃下预回火10～40min+600℃回火后H13钢的的位错密度更低，660℃下预回火10～40min+600℃回火处理可以同时提高硬度和冲击韧性，其原因是较低位错密度和较小尺寸回火析出相的共同作用。更多还原

【Abstract】 Quenched H13 steel was pre-tempered at 620,640,660,680℃ for 10,20,40 min and tempered at 600 ℃ for 120 min.By comparing with those of the steel after conventional tempering(tempering at 600 ℃ for120 min,twice),the effect of pre-tempering process on the microstructure and properties of H13 steel was studied.The results show that with the increase of pre-tempering temperature and the extension of holding time,the degree of martensitic decomposition in H13 steel increased,the amount of residual austenite decreased,the size of precipitated carbide increased,and the dislocation density decreased;the hardness of H13 steel decreased,and the impact absorption work increased,Compared with that after conventional tempering at 600 ℃,the dislocation density of H13 steel was higher after pre-tempering at 620,640 ℃ for 10-20 min and tempering at 600 ℃,and lower after pre-tempering at 660,680 ℃ for 10-40 min and tempering at 600 ℃.Pre-tempering at 660 ℃ for 10-40 min and tempering treatment could improve both hardness and impact toughness,which was due to the combined effect of lower dislocation density and smaller tempered precipitated phase.更多还原