-70℃超低温环境用钢09MnNiDR的组织性能  

Microstructure and properties of 09MnNiDR steel for-70℃ultra low temperature environment

作　　者：冯路路 胡锋[1,3] 乔文玮 鲁修宇 FENG Lu-lu;HU Feng;QIAO Wen-wei;LU Xiu-yu(The State Key Laboratory for Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;School of Mechanical Engineering,Jing Chu University of Technology,Jingmen 448000,Hubei,China;Collaborative Innovation Center for Advanced Steels,Wuhan Universityof Science and Technology,Wuhan 430081,China;Jiangsu Huaneng Cable Co.,Ltd.,Gaoyou 225613,Jiangsu,China;Longwood Research Institute,Research Institute of Wuhan Iron and Steel Group,Wuhan 430080,Hubei,China)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点实验室,湖北武汉430081 [2]荆楚理工学院机械工程学院,湖北荆门448000 [3]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,湖北武汉430081 [4]江苏华能电缆股份有限公司,江苏高邮225613 [5]武汉钢铁(集团)研究院长材研究所,湖北武汉430080

出　　处：《钢铁》2020年第10期89-95,共7页Iron and Steel

基　　金：湖北省教育厅科学技术研究资助项目(B2019216);荆楚理工学院校级科研资助项目(PY202004)。

摘　　要：09MnNiDR作为-70℃超低温环境钢,少镍低成本属性引起了广泛的关注,细化铁素体晶粒和球化渗碳体为其提高低温冲击韧性的主要方法。为了探究微观组织对其综合力学性能的影响,采用3种不同热处理工艺对09MnNiDR钢进行了试验,利用光学显微镜、扫描显微镜、拉伸试验机和低温冲击韧性试验机对试验钢的微观组织形貌进行了观察和力学性能的测定。结果表明,试验钢经正火后晶粒得到了细化,铁素体晶粒度为13级,-70℃低温冲击韧性不小于25J,韧脆转变温度为-70^-80℃;试验钢正火加热保温出炉后采用风冷加速冷却能进一步细化晶粒,铁素体晶粒度达到14级,强度和韧性同时得到了提高,韧脆转变温度降低至-80^-90℃;试验钢经正火+回火处理后,正火形成的片状或短棒状渗碳体在回火时发生了球化转变为颗粒状,对比正火态强度出现了下降,低温冲击韧性得到了进一步的提高,韧脆转变温度降低至-100℃以下。不同的生产企业可以选择合适的热处理工艺来提高09MnNiDR的低温冲击韧性,满足用户的特殊需求。As a-70℃ultra-low temperature steel,09MnNiDR has attracted a lot of attention due to its low cost and low Ni content.Refining ferrite grains and spheroidizing cementite are the main methods to improve its low temperature impact toughness.In order to investigate the effect of microstructure on its comprehensive mechanical properties,three different heat treatment processes were used.The microstructure of the test steel were observed by optical microscope,scanning microscope,and the mechanical properties of the test steel were test by tensile testing machine and low temperature impact toughness testing machine.The results showed that the ferrite grain size of the test steel was refined after normalizing,the grain size is grade 13,the-70℃low temperature impact toughness no less than 180J,and the ductile-brittle transition temperature is between-70℃and-80℃.The grain size of test steel is further refined after normalizing+accelerated cooling by wind,the grain size is grade 14,both the strength and toughness are improved,and the ductile-brittle transition temperature is between-80℃and-90℃.Test steel after normalizing+tempering,the lamellar or short rod cementite formed by normalizing degenerates into granular cementite,the strength is decreased and the low temperature impact toughness is improved,and the ductile-brittle transition temperature is decreased to-100℃.Different production enterprises can choose the appropriate heat treatment process to improve the low temperature impact toughness of 09 MnNiDR,to meet the special needs of users.

关 键 词：-70℃ 超低温 09MnNiDR 晶粒尺寸 正火 正火+回火 

分 类 号：TG142.1[一般工业技术—材料科学与工程]