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收稿：2025-02-23，
修回：2025-03-06，
纸质出版：2025-06-20
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P92钢广泛应用于超超临界机组高温部件，其焊接接头性能关乎机组安全稳定运行。然而，长期高温服役下P92钢焊接接头易出现IV型蠕变开裂问题，现有研究多采用加速蠕变试验，缺乏对实际长期服役焊接接头的研究。以国内某电厂服役70 000 h的主蒸汽管道P92钢焊接接头为研究对象，运用真空光谱仪分析化学成分，借助扫描电镜（SEM）、能谱仪（EDS）和电子背散射衍射（EBSD）观察显微组织并测量维氏硬度。研究结果表明，细晶区是IV型失效的主要区域，存在大量蠕变孔洞和微裂纹，其附近聚
集着大尺寸的Laves和M
23
C
6
相，这两种相的粗化促进了蠕变孔洞的成核和生长，还削弱了弥散强化和固溶强化。此外，焊接接头IV型裂纹侧硬度呈梯度分布，细晶区硬度最低值为150 HV，平均硬度值为175 HV，软化程度高。该研究针对实际长期服役的P92钢焊接接头开展全面研究，为准确掌握其IV型蠕变开裂机制提供了重要依据，有助于电力行业制定更合理的检测、维护策略，保障机组安全稳定运行，在电力设备材料性能研究领域具有重要的推广应用价值。
P92 steel has found extensive applications in high - temperature components of ultra - supercritical power generation units. The integrity and performance of its welded joints are of utmost significance for the reliable and stable operation of these power - generating facilities. Nevertheless
during long - term exposure to high - temperature service conditions
the welded joints of P92 steel are highly susceptible to Type IV creep cracking
which poses a significant threat to the safety and reliability of the units. Existing research efforts have predominantly relied on accelerated creep tests
leaving a notable gap in the understanding of the actual long - term service behavior of welded joints.In this study
the welded joints of P92 steel in the main steam pipeline of a domestic power plant with 70
000 hours of service were selected as the research subject. The chemical composition was precisely analyzed using a vacuum spectrometer. The microstructure was comprehensively characterized by means of a scanning electron microscope (SEM)
an energy - dispersive spectrometer (EDS) and electron backscatter diffraction (EBSD). Moreover
the Vickers hardness was accurately measured to evaluate the mechanical properties of different regions.The experimental results revealed that the fine - grained zone served as the primary location for Type IV failure. This region was filled with numerous creep pores and micro - cracks. Large - sized Laves and M23C6 phases were prominently aggregated adjacent to the fine - grained zone. The coarsening of these two phases not only significantly promoted the nucleation and growth of creep pores but also effectively diminished the dispersion strengthening and solid - solution strengthening effects. Additionally
the hardness distribution on the Type IV crack - affected side of the welded joint exhibited a distinct gradient. The minimum hardness value within the fine - grained zone was measured at 150 HV
with an average value of 175 HV
indicating a substantial degree of softening.This research conducted a comprehensive and in - depth investigation into the long - term service behavior of P92 steel welded joints. The findings provided a crucial foundation for accurately deciphering the Type IV creep cracking mechanism. Such insights are instrumental for the power industry to formulate more scientific and reasonable inspection and maintenance strategies
thereby ensuring the safe and stable operation of power generation units. The research outcomes hold great promise for wide - scale application and promotion in the field of power equipment material performance research.
Mao J ， Li X ， Wang D ， et al . Experimental study on creep-fatigue behaviors of chinese P92 steel with consideration of several important factors ［J］. International Journal of Fatigue ， 2021 ， 142 ： 105900 .
Shang C G ， Wang M L ， Zhou Z C ， et al . The microstructure evolution and its effect on creep behaviors in P92 steel under different stresses ［J］. Materials Characterization ， 2023 ， 198 ： 112744 .
Zhao L ， Xu L ， Han Y ， et al . Analysis on stress‐strain behavior and life prediction of P92 steel under creep‐fatigue interaction conditions ［J］. Fatigue & Fracture of Engineering Materials & Structures ， 2020 ， 43 （ 11 ）： 2731 - 2743 .
Xue W ， Pan Q ， Ren Y ， et al . Microstructure and type IV cracking behavior of HAZ in P92 steel weldment ［J］. Materials Science and Engineering：A ， 2012 ， 552 ： 493 - 501 .
Samuel E I ， Choudhary B K ， Palaparti D P R ， et al . Creep deformation and rupture behaviour of P92 steel at 923 K ［J］. Procedia Engineering ， 2013 ， 55 ： 64 - 69 .
Shi R ， Liu Z . Hot deformation behavior of P92 steel used for ultra-super-critical power plants ［J］. Journal of Iron and Steel Research ， International， 2011 ， 18 （ 7 ）： 53 - 58 .
Sklenička V ， Kuchařová K ， Král P ， et al . The effect of hot bending and thermal ageing on creep and microstructure evolution in thick-walled P92 steel pipe ［J］. Materials Science and Engineering：A ， 2015 ， 644 ： 297 - 309 .
Zhao L ， Hongyang J ， Xu L ， et al . Investigation on mechanism of type IV cracking in P92 steel at 650 ℃ ［J］. Journal of Materials Research ， 2011 ， 26 （ 7 ）： 934 - 943 .
Dak G ， Guguloth K ， Vidyarthy R S ， et al . Creep rupture study of dissimilar welded joints of P92 and 304L steels ［J］. Welding in the World ， 2024 ： 1 - 24 .
Seo W G ， Suh J Y ， Singh A ， et al . Microstructural evolution of P92 steel in IN740H/P92 dissimilar weld joints during creep deformation ［J］. Materials Science and Engineering：A ， 2021 ， 821 ： 141614 .
Yong L ， Jiaqing W ， Junjian L ， et al . Microstructure and Mechanical Property Changes of P92 Steel for Main Steam Pipe in Ultra-supercritical Power Plant After Long-Term Service at High Temperature ［J］. Journal of Materials Engineering and Performance ， 2024 ， 33 （ 10 ）： 4911 - 4919 .
Zhang X Z ， Wu X J ， Liu R ， et al . Influence of Laves phase on creep strength of modified 9Cr-1Mo steel ［J］. Materials Science and Engineering：A ， 2017 ， 706 ： 279 - 286 .
Wang Y ， Kannan R ， Li L . Insight into Type IV cracking in Grade 91 steel weldments ［J］. Materials & Design ， 2020 ， 190 ： 108570 .
Wang X ， Wang X ， Luo B ， et al . Analysis of cavity evolution in 9%Cr heat-resistant steel welded joint during creep ［J］. Engineering Fracture Mechanics ， 2018 ， 202 ： 394 - 404 .
Wang Y ， Kannan R ， Li L . Characterization of as-welded microstructure of heat-affected zone in modified 9Cr-1Mo-V-Nb steel weldment ［J］. Materials Characterization ， 2016 ， 118 ： 225 - 234 .
Liu Q ， Jensen D J ， Hansen N . Effect of grain orientation on deformation structure in cold-rolled polycrystalline aluminium ［J］. Acta materialia ， 1998 ， 46 （ 16 ）： 5819 - 5838 .
Wang Y ， Li L . Microstructure evolution of fine-grained heat affected zone in Type IV failure of P91 welds ［J］. Welding Journal ， 2016 ， 95 （ 1 ）： 27 - 36 .
郭苗苗 ， 刘新宝 ， 朱麟 ， 等 . 基于EBSD技术的P91钢蠕变过程中小角度晶界演化行为表征 ［J］. 材料导报 ， 2018 ， 32 （ 10 ）： 1747 - 1751 .
GUO M M ， LIU X B ， ZHU L ， et al . Characterization of small-angle grain boundary evolution during creep of P91 steel using EBSD technique ［J］. Materials Reports . 2018 ， 32 （ 10 ）： 1747 - 1751 .
Li J ， Xu C ， Zheng G ， et al . On the microstructural origin of premature failure of creep strength enhanced martensitic steels ［J］. Journal of Materials Science and Technology ， 2021 ， 87 ： 269 - 279 .
Abe F . Precipitate design for creep strengthening of 9% Cr tempered martensitic steel for ultra-supercritical power plants ［J］. Science and Technology of Advanced Materials ， 2008 ， 9 （ 1 ）： 013002 .
Abe F . Coarsening behavior of lath and its effect on creep rates in tempered martensitic 9Cr-W steels ［J］. Materials Science and Engineering：A ， 2004 ， 387-389 ： 565 - 569 .
Isik M I ， Kostka A ， Eggeler G . On the nucleation of Laves phase particles during high-temperature exposure and creep of tempered martensite ferritic steels ［J］. Acta Materialia ， 2014 ， 81 ： 230 - 240 .
Isik M I ， Kostka A ， Yardley V A ， et al . The nucleation of Mo-rich Laves phase particles adjacent to M23C6 micrograin boundary carbides in 12% Cr tempered martensite ferritic steels ［J］. Acta Materialia ， 2015 ， 90 ： 94 - 104 .
Cui H ， Sun F ， Chen K ， et al . Precipitation behavior of Laves phase in 10%Cr steel X12CrMoWVNbN10-1-1 during short-term creep exposure ［J］. Materials Science and Engineering：A ， 2010 ， 527 （ 29-30 ）： 7505 - 7509 .
Xu Y ， Wang M ， Wang Y ， et al . Study on the nucleation and growth of Laves phase in a 10% Cr martensite ferritic steel after long-term aging ［J］. Journal of Alloys and Compounds ， 2015 ， 621 ： 93 - 98 .
Xu Y ， Nie Y ， Wang M ， et al . The effect of microstructure evolution on the mechanical properties of martensite ferritic steel during long-term aging ［J］. Acta Materialia ， 2017 ， 131 ： 110 - 122 .
Fan D N ， Chen S P ， Chen L Q ， et al . Phase-field simulation of 2-D Ostwald ripening in the high volume fraction regime ［J］. Acta Materialia ， 2002 ， 50 （ 8 ）： 1895 - 1907 .
吴志方 ， 刘超 ， 周帆 . 两相体系中第二相体积分数对其Ostwald熟化的影响 ［J］. 粉末冶金工业 ， 2016 ， 26 （ 05 ）： 43 - 47 .
WU Z F ， LIU C ， ZHOU F . The effect of volume fraction of secondary phase on Ostwald ripening in two phase system ［J］. Power Metallugry Industry ， 2016 ， 26 （ 05 ）： 43 - 47 .
Lee J S ， Maruyama K . Mechanism of microstructural deterioration preceding type IV failure in weldment of Mod.9Cr-1Mo steel ［J］. Metals and Materials International ， 2015 ， 21 （ 4 ）： 639 - 645 .
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