Abstract: According to the phenomenon of segregation and conglomeration of carbides in annealed steel 3Cr17Mo (/%: 0.25C, 16.5Cr, 0.60Mn, 0.60Si, 1.0Mo, 0.020P, 0.005S) , the orthogonal experiments and discrete data analysis on effect of pre-cooling heating temperature (870~960°C., oil-cooling to 450℃),pre-cooling times (1~4) and holding time (1~4h) on structure of steel have been carried out to study the effect of repeated pre-cooling heat treatment on spheroidizing structure of steel 3Cr17Mo. It is obtained that 900~910℃ double pre-cooling heat treatment is available to decrease the time of heat treatment and get structure with uniform and fine carbides. The test results show that as compared with normal annealing process-860°C for 4h, furnace cooling to 500℃ , air cooling, the spheroidizing carbides in steel with double 900~910°C. for 30min, oil-cooling to 450℃+ annealing at 730℃ 2h and furnace cooling to 400°C air cooling is more uniform and fine, its comprehensive mechanical properties improve obviously.

摘要： 针对退火3Cr17Mo钢（/%:0.25C,16.5Cr,0.60Mn,0.60Si,1.0Mo,0.020P,0.005S）碳化物偏聚现象,对预冷加热温度（870~960℃油冷至450℃）,预冷次数（1~4）,保温时间（1~4h）对该钢组织影响进行正交试验和离散数据分析,以研究反复预冷热处理对3Cr17Mo钢球化组织的影响。得出900~910℃两次预冷热处理可减少热处理时间和得出均匀细小碳化物组织。通过两次900~910℃30min油冷至450℃+730℃2h退火炉冷至400℃空冷的试验表明,预冷处理工艺较860℃4h,炉冷至500℃空冷的常规退火工艺钢中球化碳化物分布更均匀、细小,综合力学性能明显提高。

关键词: 马氏体不锈钢3Cr17Mo, 碳化物球化组织, 预冷热处理, 等温球化退火