双相区加速冷却处理对X80管线钢组织与性能的影响  

Effect of dual phase accelerated cooling on microstructure and properties of X80 pipeline steel

作　　者：马静[1,2] 于柏青 王申豪 范利锋 Ma Jing;Yu Baiqing;Wang Shenhao;Fan Lifeng(School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang Hebei 050018,China;Hebei Key Laboratory of Material Near-Net Forming Technology,Shijiazhuang Hebei 050018,China;School of Transportation,Inner Mongolia University,Hohhot Inner Mongolia 010070,China)

机构地区：[1]河北科技大学材料科学与工程学院,河北石家庄050018 [2]河北省材料近净成形技术重点实验室,河北石家庄050018 [3]内蒙古大学交通学院,内蒙古呼和浩特010070

出　　处：《金属热处理》2020年第3期140-146,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(51761030,51701064)。

摘　　要：采用双相区加速冷却法(加速冷却始冷温度为700℃)对X80管线钢进行热处理,获得了贝氏体和铁素体(B+F)双相组织。然后通过组织表征、力学性能测试以及在3.5wt%Na Cl溶液中的耐蚀性进行研究。结果表明:热处理后获得的管线钢组织由板条状贝氏体、多边形铁素体及少量马氏体/奥氏体岛组成。与热处理前相比,(B+F)双相管线钢屈强比较低,为0.65,初始加工硬化指数为0.31,均匀伸长率达8.3%,塑性显著提升;双相组织中含有52.4%的铁素体,因而耐腐蚀性明显提高。通过双相区加速冷却法获得的(B+F)两相组织在塑变过程中发生协调变形,可以适应大变形的需求,同时耐蚀性优异,为大变形管线钢实际生产提供一定的借鉴。X80 pipeline steel was heat treated by using dual phase accelerated cooling(the initial cooling temperature of the accelerated cooling was 700℃),and dual-phase structure of bainite and ferrite(B+F)was obtained.Microstructure characterization,mechanical properties test and corrosion resistance in 3.5 wt%Na Cl solution were studied.The results show that the microstructure of pipeline steel after heat treatment is composed of lath bainite,polygonal ferrite and a small amount of martensite/austenite islands.The yield ratio and initial work hardening index of(B+F)dual-phase pipeline steel are 0.65 and 0.31,respectively.Compared with that of steel before heat treatment,the uniform elongation of pipeline steel after heat treatment is 8.3%,which indicates that the ductility is significantly improved.The corrosion resistance is also improved due to 52.4%amount of ferrite phase in the dual-phase structure.The coordinated deformation of(B+F)dual-phase structure obtained by dual-phase accelerated cooling during plastic deformation process can meet the needs of high deformation,and the corrosion resistance of the dual-phase structure is excellent,which provides some reference for the actual production of high deformation pipeline steel.

关 键 词：双相区加速冷却法 X80管线钢 B+F双相组织 大变形 均匀伸长率 

分 类 号：TG156.3[金属学及工艺—热处理]