轧后冷却制度对低碳贝氏体钢组织及屈强比的影响  

Effect of Cooling Process After Rolling on Microstructure and Yield Ratio of Low Carbon Bainite Steel

作　　者：王克鲁[1] 鲁世强[1] 李鑫[1] 郑海忠[1] 董显娟[1] 

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《热加工工艺》2008年第16期15-17,共3页Hot Working Technology

基　　金：江西省自然科学基金资助项目(0605123)

摘　　要：在热模拟及轧制实验的基础上,利用扫描电镜和多功能材料试验机研究了轧后冷却制度对低碳贝氏体钢组织及屈强比的影响。结果表明,所研究钢种在1～25℃/s的冷却速度范围内均可得到贝氏体组织,其贝氏体开始转变温度为557～651℃。轧后以不同冷却制度冷却至室温的试样微观组织主要为板条贝氏体、粒状贝氏体、准多边形铁素体等的混合组织,冷却制度不同,各种组织所占的比例有很大不同。冷却制度对屈强比也有明显影响;轧后直接空冷至室温的试样的屈强比为0.68,但强度较低;油淬试样的屈强比约0.77,且强度较高;水冷至531℃而后空冷的试样的屈服强度较高,但抗拉强度相对较低,屈强比高达0.90。Based on the results of hot-simulation and rolling test, the influences of cooling process on the microstructure and yield ratio of low carbon bainite steel were studied by multi-function material testing machine and SEM. The results indicate that bainite can be formed in a wide range of cooling rates from 1 ℃/s to 25 ℃/s. The beginning transformation temperature is 557-651 ℃. As air cooling after rolling, the microstructure of specimen shows mainly quasi-polygonal ferrite and granular bainite with low strength and yield ratio （0.68）. As oil quenching after rolling, the microstructure of specimen shows mainly quasi-polygonal ferrite, granular bainite and lathe bainite with higher strength and moderate yield ratio （0.77）. As firstly water-cooling after rolling then air-cooling from 531 ℃, the microstructure of specimen shows mainly granular bainite with high yield strength and yield ratio（0.90）.

关 键 词：冷却制度 低碳贝氏体钢 组织 屈强比 

分 类 号：TG142.1[一般工业技术—材料科学与工程]