冷却制度对700MPa级低碳贝氏体钢组织与性能的影响  

Effect of cooling process on microstructure and mechanical properties of 700MPa grade low carbon bainitic steel

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

机构地区：[1]南昌航空大学材料学院,江西南昌330063

出　　处：《材料热处理学报》2008年第5期76-80,共5页Transactions of Materials and Heat Treatment

基　　金：江西省自然科学基金项目(0605123)

摘　　要：在热轧试验的基础上,采用多功能材料试验机及光学显微镜,研究了不同冷却制度对700MPa级低碳贝氏体钢组织和性能的影响。结果表明,根据冷却制度的不同,所研究低碳贝氏体钢的微观组织表现为准多边形铁素体、粒状贝氏体和板条贝氏体等的比例、形态及尺寸的不同。轧后空冷时,试样的微观组织主要为准多边形铁素体和粒状贝氏体,其强度较低,但塑性较好;轧后水冷时,试样的微观组织主要为板条贝氏体,具有较高的强度和较低的伸长率;轧后油淬时,试样的微观组织主要为板条贝氏体、粒状贝氏体、准多边形铁素体及针状铁素体的复合组织,这种组织具有较好的强度和塑性配合;轧后水冷至531℃而后空冷至室温时,试样的微观组织主要为粒状贝氏体,具有高的屈服强度和屈强比。Based on the results of hot rolling on a laboratory mill,the influence of cooling process on the microstructure and mechanical properties of a 700MPa grade low carbon bainitic steel was studied by using multi-function material testing machine and optical microscope.The results indicate that the microstructure of low carbon bainitic steel consists of quasi-polygonal ferrite,granular bainite and lath bainite of different proportion and size for different cooling process.As air cooling after rolling,the microstructure of specimen consists of mainly quasi-polygonal ferrite and granular bainite with low strength and moderate ductility.As water-cooling after rolling,the microstructure of specimen is composed of mainly lath bainite with high strength and low elongation.As oil quenching after rolling,the microstructure of quasi-polygonal ferrite,granular bainite,lath bainite and acicular ferrite is observed in the specimen with higher strength and preferable ductility.As firstly water-cooling after rolling to 531℃ and then air cooling to room temperature,the microstructure of specimen consists of mainly granular bainite with high yield strength and high ratio of yield strength to tensile strength.

关 键 词：冷却制度 低碳贝氏体钢 组织 性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]