锰含量对3Cr4MoSiV 热锻模具钢抗回火软化能力的影响

摘要

Tempering treatments at 550 ℃ and 650 ℃ were carried out on hot forging die steel 3Cr4MoSiV samples containing 1.20wt%,2.00wt% and 4.00wt% Mn,and the effect of Mn content on tempering softening resistance of the steel was investigated by means of transmission electron microscopy, scanning electron microscopy,hardness testing and so on.The results show that tempering softening resistance was the most excellent when Mn content was 1.2wt%.Increasing Mn content was good for improving tempering softening resistance of the steel after tempering at 550 ℃ for short time,but decreasing that after tempering at 550 ℃ for a long time and at 650 ℃.After tempering at 650 ℃,tempering softening resistance of the steel containing above 1.20wt% Mn greatly decreased mainly,this was due to the more content of Mn promoting carbide coarsening.%对锰质量分数分别为1．20％,2．00％和4．00％的3Cr4MoSiV 热锻模具钢在550℃和650℃进行回火处理,然后利用高分辨透射电镜(TEM)、场发射扫描电镜(SEM)、硬度仪等研究了锰含量对其抗回火软化能力的影响.结果表明：当锰质量分数为1．20％时,试验钢的抗回火软化能力最佳；锰含量增加有利于该钢在550℃短时间回火过程抗回火软化能力的提高,但却使550℃长时间回火过程及650℃回火过程的抗回火软化能力降低；锰质量分数大于1．20％的试验钢在650℃回火过程中,抗回火软化能力大大降低,这是因为较多锰元素的加入促进了碳化物粗化.