工程科学学报，第39卷，第4期：529534,2017年4月 Chinese Journal of Engineering,Vol.39,No.4:529-534,April 2017 DOI:10.13374/j.issn2095-9389.2017.04.007:http://journals.ustb.edu.cn 回火次数对P91焊管接头力学性能的影响 王 超2》，党文静2)四，鲁路2》，王瑜)，崔征”，王伟博 1)西安建筑科技大学治金工程学院，西安7100552)陕西省治金工程技术研究中心，西安710055 3)陕西省锅炉压力容器检验所，西安710048 ☒通信作者，E-mail:dwjaef(@163.com 摘要采用光学显微镜、X射线衍射分析、透射电镜、选区电子衍射及常温与高温拉伸试验等检测手段，基于不同回火次数 下91焊接接头显微组织的演化过程研究其对力学性能的影响.结果表明，随着回火次数的增多，接头显微组织主要保留了 板条马氏体位向的回火索氏体，主要相为aFe相和FeC:相，热影响区的室温及高温强度先增大后减小.在回火一次时，弥 散析出的MX(M=VNb,X=CN)型碳氮化物、位错缠结及亚稳态的位错网对接头有一定的析出强化及位错强化作用，其力 学性能较佳，高温抗拉强度达最大值232.66MP:随着回火次数进一步增多，离散分布的碳化物Cr2C6逐渐偏聚并在晶界处 演化为串链状分布，使晶界脆化，强度降低，但韧性有所改善 关键词无缝管：焊接接头：回火：微观组织：高温力学性能 分类号TG156.5 Influence of tempering times on the mechanical properties of P91 weld joints WANG Chao'2,DANG Wen-jing2a,LULa,WANG YL》,CUl Zheng》,WANG Wei-bo” 1)School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xian 710055,China 2)Shanxi Province Metallurgical Engineering and Technology Research Center,Xi'an 710055,China 3)Shanxi Institute of Inspection on Boiler&Pressure Vessel,Xi'an 710048,China Corresponding author,E-mail:dwjaef@163.com ABSTRACT The P91 weld joint used in the experiment is re-tempered according to the heat treatment process.The effect of tempe- ring times on its mechanical properties,including that at room temperature and high temperature,was then investigated in relation to the evolution of its microstructure using optical microscopy (OM),X-ray diffraction (XRD),transmission electron microscopy (TEM),selected area electron diffraction (SAED),and tensile tests.Results indicate that the strength at room and high temperature of the heat affected zone increases first and then decreases with an increase in tempering times.In addition,the microstructure is still tempered sorbite that reserves the orientation of lath martensite,and the main phases are the a-Fe phase and Fe-Cr phase.After being tempered once,its high-temperature tensile strength reaches a maximum of 232.66 MPa.These improved mechanical properties relate to the dispersed distribution of niobium and vanadium carbonitride precipitate particles,dislocation tangles,and dense metastable dislocation networks.With the increase of tempering times,the distribution of CraC precipitates gradually undergoes a change from being isolated to displaying a continuous manner in the grain boundaries;this can embrittle the grain boundary and reduce the strength while improving toughness. KEY WORDS seamless pipe:weld joints:tempering:microstructure:high temperature mechanical properties P91钢是在9CH1Mo钢的基础上，限制C含量，并理论开发而成的的一种新型铁素体耐热钢，其供货 加以微量N、V和Nb元素，应用固溶强化和弥散强化状态为马氏体，我国对应牌号为10C9 Mol VNI1-四. 收稿日期：2016-07-11 基金项目：国家质检总局科技计划资助项目(SNOTS.2013QK148)工程科学学报，第 39 卷，第 4 期: 529--534，2017 年 4 月 Chinese Journal of Engineering，Vol． 39，No． 4: 529--534，April 2017 DOI: 10． 13374 /j． issn2095--9389． 2017． 04． 007; http: / /journals． ustb． edu． cn 回火次数对 P91 焊管接头力学性能的影响 王 超1，2) ，党文静1，2) ，鲁 路1，2) ，王 瑜3) ，崔 征1) ，王伟博1) 1) 西安建筑科技大学冶金工程学院，西安 710055 2) 陕西省冶金工程技术研究中心，西安 710055 3) 陕西省锅炉压力容器检验所，西安 710048 通信作者，E-mail: dwjaef@ 163． com 摘 要 采用光学显微镜、X 射线衍射分析、透射电镜、选区电子衍射及常温与高温拉伸试验等检测手段，基于不同回火次数 下 P91 焊接接头显微组织的演化过程研究其对力学性能的影响． 结果表明，随着回火次数的增多，接头显微组织主要保留了 板条马氏体位向的回火索氏体，主要相为 α-Fe 相和 Fe-Cr 相，热影响区的室温及高温强度先增大后减小． 在回火一次时，弥 散析出的 MX( M = V/Nb，X = C/N) 型碳氮化物、位错缠结及亚稳态的位错网对接头有一定的析出强化及位错强化作用，其力 学性能较佳，高温抗拉强度达最大值 232. 66 MPa; 随着回火次数进一步增多，离散分布的碳化物 Cr23 C6逐渐偏聚并在晶界处 演化为串链状分布，使晶界脆化，强度降低，但韧性有所改善． 关键词 无缝管; 焊接接头; 回火; 微观组织; 高温力学性能 分类号 TG156. 5 收稿日期: 2016--07--11 基金项目: 国家质检总局科技计划资助项目( SNQTS_2013QK148) Influence of tempering times on the mechanical properties of P91 weld joints WANG Chao1，2) ，DANG Wen-jing1，2)  ，LU Lu1，2) ，WANG Yu3) ，CUI Zheng1) ，WANG Wei-bo1) 1) School of Metallurgical Engineering，Xi'an University of Architecture and Technology，Xi'an 710055，China 2) Shanxi Province Metallurgical Engineering and Technology Ｒesearch Center，Xi'an 710055，China 3) Shanxi Institute of Inspection on Boiler ＆ Pressure Vessel，Xi'an 710048，China  Corresponding author，E-mail: dwjaef@ 163． com ABSTＲACT The P91 weld joint used in the experiment is re-tempered according to the heat treatment process． The effect of tempe￾ring times on its mechanical properties，including that at room temperature and high temperature，was then investigated in relation to the evolution of its microstructure using optical microscopy ( OM) ，X-ray diffraction ( XＲD) ，transmission electron microscopy ( TEM) ，selected area electron diffraction ( SAED) ，and tensile tests． Ｒesults indicate that the strength at room and high temperature of the heat affected zone increases first and then decreases with an increase in tempering times． In addition，the microstructure is still tempered sorbite that reserves the orientation of lath martensite，and the main phases are the α-Fe phase and Fe--Cr phase． After being tempered once，its high-temperature tensile strength reaches a maximum of 232. 66 MPa． These improved mechanical properties relate to the dispersed distribution of niobium and vanadium carbonitride precipitate particles，dislocation tangles，and dense metastable dislocation networks． With the increase of tempering times，the distribution of Cr23 C6 precipitates gradually undergoes a change from being isolated to displaying a continuous manner in the grain boundaries; this can embrittle the grain boundary and reduce the strength while improving toughness． KEY WOＲDS seamless pipe; weld joints; tempering; microstructure; high temperature mechanical properties P91 钢是在 9Cr--1Mo 钢的基础上，限制 C 含量，并 加以微量 N、V 和 Nb 元素，应用固溶强化和弥散强化 理论开发而成的的一种新型铁素体耐热钢，其供货 状态为马氏体，我国对应牌号为 10Cr9Mo1VNb［1--2］．