氮含量对钒微合金钢粗晶热影响区组织和韧性的影响  

Effect of Nitrogen on Microstructure and Toughness of Coarse Grain Heat Affected Zone in Vanadium Microalloyed Steel

作　　者：师仲然 潘涛[1] 王瑞珍[1] 王东明 赵和明 罗小兵[1] 柴锋[1] 杨才福[1] SHI Zhongran;PAN Tao;WANG Ruizhen;WANG Dongming;ZHAO Heming;LUO Xiaobing;CHAI Feng;YANG Caifu(Department of Structural Steels,Central Iron and Steel Research Institute,Beijing 100083,China;Rizhao Steel Yingkou Medium Plate Co.,Ltd.,Yingkou 115000,China)

机构地区：[1]钢铁研究总院工程用钢研究院,北京100081 [2]日钢营口中板有限公司,辽宁营口115000

出　　处：《材料开发与应用》2022年第2期10-18,共9页Development and Application of Materials

基　　金：山东省自然科学基金(ZR201911170022);辽宁省科技重大专项项目(No.2019JH/10100014);山东省重点研发计划(重大科技创新工程(2020CXG010305))。

摘　　要：采用焊接热模拟的方法,研究了氮含量对实验钢焊接粗晶热影响区(CGHAZ)显微组织和韧性的影响规律。结果表明:随着氮含量的增加,CGHAZ的组织从晶界铁素体、贝氏体和侧板条铁素体转变成针状铁素体、多边形铁素体和少量的贝氏体,且铁素体晶粒细化;CGHAZ韧脆转变温度(FATT_(50))先降低后升高,屈服强度升高。氮含量从0.004 4%增加到0.009 4%时,有效晶粒尺寸减小,导致CGHAZ的FATT_(50)降低;氮含量从0.009 4%增加到0.019 0%时,CGHAZ中固溶氮、屈服强度增量对FATT_(50)的综合作用大于晶粒的细化作用,导致FATT_(50)升高。Microstructures and toughness of coarse grain heat affected zones(CGHAZ) in experimental steels with different nitrogen contents are studied by welding thermal simulation. Results indicate that with the increase of nitrogen content, CGHAZ microstructure changes from grain boundary ferrite, bainite and side lath ferrite to acicular ferrite, polygonal ferrite and a small amount of bainite, with the ferrite grains refined. The ductile-brittle transition temperature(FATT_(50)) of CGHAZ steel decreases first and then increases, meanwhile the yield strength rises. When the nitrogen content increases from 0.004 4% to 0.009 4%, the effective grain size decreases and the FATT_(50)of CGHAZ decreases. When the nitrogen content increases from 0.009 4% to 0.019 0%, the combined influence of solid solution nitrogen and yield strength increment on FATT_(50)is greater than that of grain refinement, leading to the increase of FATT_(50).

关 键 词：钒微合金钢 氮含量 组织 低温韧性 

分 类 号：TG142.74[一般工业技术—材料科学与工程]