服役后P92钢管不同硬度区的显微结构及拉伸性能  

Microstructure and tensile properties of different hardness regions in as-served P92 steel pipe

作　　者：李勇 马佳林 王万里 方一鸣 占先强 刘俊建 汤文明[3] Li Yong;Ma Jialin;Wang Wanli;Fang Yiming;Zhan Xianqiang;Liu Junjian;Tang Wenmin(Datang Boiler Pressure Vessel Inspection Center Co.,Ltd.,Hefei Anhui 230088,China;East China Electric Power Test and Research Institute,China Datang Corporation Science and Technology General Research Institute Ltd.,Hefei Anhui 230088,China;School of Materials Science and Engineering,Hefei University of Technology,Hefei Anhui 230009,China)

机构地区：[1]大唐锅炉压力容器检验中心有限公司,安徽合肥230088 [2]中国大唐集团科学技术研究总院有限公司华东电力试验研究院,安徽合肥230088 [3]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《金属热处理》2024年第10期140-147,共8页Heat Treatment of Metals

摘　　要：某超(超)临界机组服役7万小时的P92主蒸汽管外表面硬度偏低部位径向截面不同区域处的硬度存在明显差异。采用显微分析、物相分析及室温、高温拉伸性能测试,确定不同硬度区域试样的显微结构与力学性能的特征。结果表明,低硬度试样中的马氏体板条宽化、分解更明显,逐渐向回火索氏体组织转变;在原奥氏体晶界及马氏体板条界析出的M_(23)C_(6)、Laves相颗粒愈加粗化,呈半连续的链状分布;同时在马氏体板条和(或)铁素体内弥散分布的析出相尺寸也较大。低硬度试样的室温、高温拉伸强度低,其室温和高温屈服强度已达不到标准的要求,可作为服役P92主蒸汽管老化状态评估时重点考核的力学性能指标。Remarkable hardness difference was found in the cross-sectional regions of low outside surface hardness in P92 main steam pipe after serving for 70000 h.Microscopic and phase analysis,and room-/high-temperature tensile property tests were executed to confirm the microstructure characteristics and mechanical properties of the specimens in different hardness regions.The results show that for the low hardness specimens,widening and decomposing of martensite lathes is severe,lath martensite is gradually transferred to tempered martensite.The M_(23)C_(6)and Laves-phase particles precipitated along the prior austenite grain boundaries and martensite lathes are further coarsened and distributed in semi-continuous chains.Meanwhile,the precipitated phase particles dispersively distributed in the martensite and(or)ferrite matrices are also expanded.The room and high temperature tensile strengths of the low hardness specimens are low too,especially,room and high temperature yield strengths of them are lower than the indexes required by the relevant national standards,which could be used for the key mechanical property index in aging state assessment of the as-served P92 main-steam pipe.

关 键 词：超(超)临界机组 P92钢管 板条马氏体 析出相 硬度 拉伸性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]