临界淬火对超厚水电钢冲击韧性的影响  

Effect of critical quenching on impact toughness of ultra-thick Hydropower Steel

作　　者：陈星宇 冯路路 宋增强 乔文玮 李萍萍 吴开明[1] Chen Xinyu;Feng Lulu;Song Zengqiang;Qiao Wenwei;Li Pingping;Wu Kaiming(Collaborative Innovation Center on Advanced Steels,Wuhan University of Science and Technology,Wuhan 430081,China;School of Mechanical Engincering,Jing Chu University of Technology,Jingmen 448000,China;Jiangsu Huaneng Cable Co.,Ltd.,Gaoyou 225613,China;Marketing Center,Bejing Shougng Ca,Ltd.,Bejing 100043,China)

机构地区：[1]武汉科技大学高性能钢铁材料及其应用省部共建协同创新中心,武汉430081 [2]荆楚理工学院机械工程学院,湖北荆门448000 [3]江苏华能电缆股份有限公司,江苏高邮225613 [4]北京首钢股份有限公司营销中心,北京100043

出　　处：《材料与冶金学报》2021年第3期211-216,共6页Journal of Materials and Metallurgy

基　　金：武汉科技大学研究生创新创业项目(JXC202002);荆楚理工学院校级科研项目(PY202004,YB201902)。

摘　　要：通过设计对比实验,研究了临界淬火工艺对超厚水电站用钢板的组织和性能的影响.试验结果发现,临界淬火较低的加热温度得到了细小的奥氏体晶粒和一定量的未溶铁素体,临界淬火后试验钢近表面得到了未溶铁素体+板条马氏体组织,厚度t/4处得到了未溶铁素体+板条贝氏体+粒状贝氏体组织,厚度t/2处得到未溶铁素体+先共析铁素体+粒状贝氏体组织.回火后钢板近表面组织转变为未溶铁素体+回火索氏体组织,厚度t/4和t/2处回火后得到了铁素体+回火贝氏体组织.临界淬火工艺保留了部分未溶铁素体,使碳扩散至奥氏体中,提高了奥氏体的稳定性,淬火后以残余奥氏体存在,提高了超厚水电钢的冲击韧性;厚度t/2处的-20℃的低温冲击韧性达到了156 J,满足了使用要求.The effect of critical quenching on the low temperature impact toughness of the ultra-thick low-carbon bainite steel was studied by designing comparative experiments.The results show that fine austenite grains and undissolved ferrite are obtained at low heating temperature during critical quenching.After critical quenching,undissolved ferrite and lath martensite are obtained near the surface of the steel,and undissolved ferrite+lath bainite+granular bainite is obtained at the t/4 thickness of test steel,and undissolved ferrite+proeutectoid ferrite+granular bainite is obtained at the t/2 thickness of test steel.After tempering,the near surface microstructure of the steel transformation into undissolved ferrite+tempered sorbite,and the ferrite+tempered bainite microstructure is obtained after tempering at the thickness t/4 and t/2.Some undissolved ferrite is retained in the critical quenching process,which makes carbon diffuse into austenite and improves the stability of austenite.It is found that some residual austenite exists in the tested steel after critical quenching,which improves the impact toughness of ultra-thick hydropower steel.The-20℃low temperature impact toughness at t/2 thickness reaches to 156 J,which meets the application requirements.

关 键 词：临界淬火 超厚水电钢 冲击韧性 未溶铁素体 

分 类 号：TG142[一般工业技术—材料科学与工程]