冷却速度对热轧40CrMo圆钢组织的影响  

Effect of Cooling Rate on Structure of Hot Rolled Round Bar of Steel 40CrMo

作　　者：邓素怀[1] 王丽萍[1] 杨子森[1] 易敏[1] 

机构地区：[1]首钢技术研究院,北京100043

出　　处：《特殊钢》2012年第3期65-68,共4页Special Steel

摘　　要：连续式棒材轧机生产Φ70～80 mm 40CrMo系圆钢(/%:0.40～0.41C、0.97～1.05Cr、0.17Mo)时,由于轧制道次少,终轧后无控制冷却装置,易出现珠光体+铁素体和贝氏体+马氏体两种类型组织。通过Gleeble-2000热模拟试验机测试炉批No1和炉批No2这两类原始组织试样的连续冷却转变(CCT)曲线和研究了该钢1150℃保温5 min后以10℃/s冷至900℃停留10 s,以变形速率20 s^(-1)变形30%再以0.2～10℃/s冷却至200℃的组织和微区成分。结果表明,轧后冷却速度大则产生马氏体组织,40CrMo系圆钢在0.1～1℃/s冷却速度下可获得正常的贝氏体组织和珠光体组织。Owing to less rolling passes and non-control cooling rate device after finishing rolling,the two kinds of structure-pearlite ＋ ferrite and bainite ＋ martensite inΦ70～80 mm round bar of steel 40CrMo（/%：0.40～0.41C, 0.97～1.05Cr,0.17Mo） produced by continuous rolling mill strain easily occur.By using Gleeble-2000 thermal simulation machine the continuous cooling transformation（CCT） curves of two kinds of original structure specimens of heat batch No1 and No2 are measured,and the structure and micro-region analysis of finished products by heating at 1 150℃for 5 min then cooling with 10℃/s to 900℃for 10 s and deforming 30%with strain rate 20 s^（-1） and cooling with 0.2～10℃/s to 200℃are studied.Results show that the martensite structure occurs as the finished products is cooling with large cooling rate after rolling;with cooling speed 0.1～1℃/s for round bar after rolling the steel 40CrMo can get normal structure i.e.bainite and/or pearlite structure.

关 键 词：40CrMo钢 圆棒材 热轧 冷却速度 组织 

分 类 号：TG335.12[金属学及工艺—金属压力加工]