中温压力容器钢12CrMo的高温塑性研究  

Hot ductility of mid-temperature pressure vessel steel 12CrMo

作　　者：李具中[1,2] 余宏伟[1] 陈晓[2] 习天辉[2] 吴开明[1] 

机构地区：[1]武汉科技大学冶金工业过程系统科学湖北省重点实验室,湖北武汉430081 [2]武汉钢铁(集团)公司炼钢总厂,湖北武汉430081

出　　处：《武汉科技大学学报》2010年第3期229-232,共4页Journal of Wuhan University of Science and Technology

基　　金：教育部新世纪优秀人才支持计划项目(NCET-05-0680);湖北省自然科学基金计划青年杰出人才项目(2006ABB037)

摘　　要：通过热模拟试验对中温压力容器钢12CrMo连铸坯的高温塑性进行研究。在不同的变形温度下采用10-3s-1的应变速率对试样进行拉伸变形,测量拉伸断口的面缩率,并对拉伸断口的显微组织和析出物进行分析。结果表明,当变形温度高于900℃时,试样在拉伸过程中发生动态再结晶,其面缩率大于85%,表现出优良的高温塑性;当变形温度为850℃时,有大量细小的AlN在12CrMo钢中弥散析出,其尺寸约为10 nm;当变形温度降至800℃时,大量的先共析铁素体沿奥氏体晶界析出,形成网状结构,试样面缩率降至36%,12CrMo钢的高温塑性显著下降。The hot ductility of 12CrMo continuously cast slabs used for mid-temperature pressure vessel steel was investigated on a Gleeble-3500 by means of tensile test,which was carried out at varying temperatures with a strain rate of 10-3 s-1.Fracture area reduction ratio was measured and microstructures and precipitates were examined.It is found that dynamic recrystallization occurs when specimens are deformed above 900 ℃,and thus the steel has good ductility with the area reduction ratio≥85%.A large amount of fine AlN is precipitated,the size being approximately 10 nm,when specimens are deformed at 850 ℃.A lot of proeutectiod ferrite grains form along austenite grain boundaries when specimens are deformed at 800 ℃,and consequently,the steel has poor hot ductility because the area reduction ratio is lowered to 36%.

关 键 词：压力容器钢 铸坯 高温塑性 氮化物 先共析铁素体 

分 类 号：TG111[金属学及工艺—物理冶金] TG142[金属学及工艺—金属学]