摘要
采用Gleeble-3500热模拟试验机模拟了Q500qENH耐候桥梁钢形变奥氏体连续冷却转变过程。采用膨胀法结合组织观察及硬度测试,绘制了钢的连续冷却转变(continuous cooling transformation,CCT)曲线。结果表明:当冷速小于1℃/s时,形成以多边形铁素体和珠光体为主、少量粒状贝氏体的混合组织;当冷速在5~15℃/s时,组织类型为粒状贝氏体和针状铁素体;当冷速大于15℃/s时,出现板条贝氏体。随着冷速的增大,组织逐渐细化,硬度逐渐增加。Q500qENH钢优选的两阶段控轧后控冷工艺窗口为5~15℃/s,在该冷速范围内形成了粒状贝氏体、针状铁素体和适度细化的M-A多相复合组织。
Continuous cooling transformation of deformed austenite in Q500qENH weathering bridge steel was investigated on Gleeble-3500 thermal simulator.By thermal dilation method combining with microstructure observation and hardness measurement,the continuous cooling transformation(CCT) curves of the steel was studied.The results showed that when the cooling rate was lower than 1 ℃/s,a mixed structure of polygonal ferrite and pearlite with a small amount of granular bainite was formed;when the cooling rate was 5 to 15 ℃/s,the microstructure was granular bainite and acicular ferrite;and when the cooling rate was greater than 15 ℃/s,lath bainite appeared.As the cooling rate increased,the structure gradually refined and the hardness gradually increased.The optimal controlled cooling process window after two-stage controlled rolling of Q500qENH steel was in the range of 5 to 15 ℃/s,and the multiphase microstructure was granular bainite,acicular ferrite,and moderately refined M-A constituent within this cooling rate range.
作者
赵丽洋
刘东博
谯明亮
陈林恒
崔强
王青峰
ZHAO Liyang;LIU Dongbo;QIAO Mingliang;CHEN Linheng;CUI Qiang;WANG Qingfeng(State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao Hebei 066004,China;National Engineering Research Center for Equipment and Technology of Cold Rolling Strip,Yanshan University,Qinhuangdao Hebei 066004,China;Nanjing Iron&Steel Company Limited,Nanjing Jiangsu 210035,China)
出处
《上海金属》
CAS
2022年第1期35-39,共5页
Shanghai Metals
基金
国家重点研发计划(No.2017YFB0304800,No.2017YFB0304802)。
