B元素含量对9Cr铁素体耐热钢组织和蠕变性能的影响  

Effects of Boron Element Content on Microstructure and Creep Properties of 9Cr Ferritic Heat-resistant Steel

作　　者：胡福勇 申俊杰[1,2] 赵庆权[3] 肖功业[3] HU Fuyong;SHEN Junjie;ZHAO Qingquan;XIAO Gongye(Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control,Tianjin University of Technology,Tianjin 300384,China;National Demonstration Center for Experimental Mechanical and Electrical Engineering Education,Tianjin University of Technology,Tianjin 300384,China;Tianjin Pipe(Group)Corporation,Tianjin 300384,China)

机构地区：[1]天津理工大学天津市先进机电系统设计与智能控制重点实验室,天津300384 [2]天津理工大学机电工程国家级实验教学示范中心,天津300384 [3]天津钢管集团股份有限公司,天津300384

出　　处：《热加工工艺》2021年第18期51-55,共5页Hot Working Technology

基　　金：国家自然科学基金项目(51605330,11602169);天津市自然科学基金项目(18JCYBJC88700)。

摘　　要：采用光学显微镜、扫描电镜、矩形单轴蠕变测试、X射线衍射研究了三种不同B含量的9Cr铁素体耐热钢正火回火后的组织特征和蠕变性能。结果表明:9Cr铁素体耐热钢的显微结构为回火马氏体;随着硼含量的增加,马氏体板条逐渐细化,M_(23)C_(6)的密度增大,平均粒径变小;随硼含量的增加,9Cr铁素体耐热钢的最小蠕变率降低,加速蠕变延缓,断裂时间增长,但伸长率降低。硼元素能有效降低M_(23)C_(6)碳化物的Orowan成熟速率,细化马氏体板条,提高9Cr铁素体耐热钢的蠕变强度。The microstructure and creep properties of 9 Cr ferritic heat resistant steels containing different content of boron after normalizing and tempering were studied by optical microscopy,scanning electron microscopy,X-ray diffraction and rectangular uniaxial creep testing.The results show that the microstructure of 9 Cr ferritic heat resistant steel is tempered martensite.As the boron content increases,the martensite lath gradually refines,the density of M_(23)C_(6)increases and the particle size becomes smaller.With the increase of boron content,the minimum creep rate decreases,the onset time of accelerated creep becomes slower and the rupture time increases,whereas,the elongation decreases.Boron is beneficial to the refinement of the tempered martensite lath structure.Boron could effectively decrease the rate of Orowan ripening of M_(23)C_(6)carbides and improve the creep strength of 9 Cr ferritic heat resistant steel.

关 键 词：M_(23)C_(6)碳化物 硼 铁素体耐热钢 蠕变强度 

分 类 号：TG113.255[金属学及工艺—物理冶金]