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Investigation on mechanism of type IV cracking in P92 steel at 650 °C

Published online by Cambridge University Press:  23 February 2011

Lei Zhao ,
Hongyang Jing ,
Lianyong Xu ,
Junchao An ,
Guangchun Xiao ,
Delu Xu ,
Yucheng Chen  and
Yu Han
Lei Zhao
Affiliation:
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; and Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China
Hongyang Jing
Affiliation:
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; and Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China
Lianyong Xu*
Affiliation:
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; and Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China
Junchao An
Affiliation:
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; and Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China
Guangchun Xiao
Affiliation:
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; and Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China
Delu Xu
Affiliation:
China Electric Power Research Institute, Beijing 100055, China
Yucheng Chen
Affiliation:
China Electric Power Research Institute, Beijing 100055, China
Yu Han
Affiliation:
China Electric Power Research Institute, Beijing 100055, China
*
a)Address all correspondence to this author. e-mail: xulianyong@tju.edu.cn
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Abstract

Welded joints of P92 steel subjected to creep testing at 650 °C and 70 MPa were investigated. Type IV cracking was observed in the fine-grained heat-affected zone (FGHAZ) of the welded joints by optical microscopy. It was found that with varying creep times, the number of creep voids increased at an accelerating rate and the maximum number of voids was formed in the FGHAZ. Scanning electron microscopy observations revealed that precipitates were formed in the interior of creep voids, suggesting that the nucleation of the creep voids is related to the precipitates. These creep voids then connected with each other, isolated the grain from the matrix, and formed zigzag microcracks, leading to type IV cracking. New coarse carbides—the Laves phase and Cr7C3—were precipitated during creep. These carbides can deteriorate the creep strength and stimulate the nucleation of creep voids in the FGHAZ.

Keywords

MicrostructureScanning Electron Microscopy (SEM)Transmission Electron Microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 7 , 14 April 2011 , pp. 934 - 943
Copyright
Copyright © Materials Research Society 2011

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References

REFERENCES

1.Abe, F., Okada, H., Wanikawa, S., Tabuchi, M., Itagaki, T., Kimura, K., Yamaguchi, K., and Igarashi, M.: Guiding principles for development of advanced ferritic steels for 650 °C USC boilers, edited by Lecoute-Beckers, J., Carton, M., Schubert, F., and Ennis, P.J., in Proc. of Seventh Liege Conference on Materials for Advanced Power Engineering (Forschungszentrum Julich, Germany, 2002), p. 1397.Google Scholar
2.Fujibayashi, S., Kawano, K., Komamura, T., and Sugimura, T.: Creep behavior of 2.25Cr–1Mo steel shield metal arc weldment. ISIJ Int. 44, 581 (2004).CrossRefGoogle Scholar
3.Vaillant, J.C., Vandenberghe, B., Hahn, B., Heuser, H., and Jochum, C.: T/P23, 24, 911 and 92: New grades for advanced coal-fired power plants–properties and experience. Int. J. Press. Vessels Pip. 85, 38 (2008).CrossRefGoogle Scholar
4.Lundin, C.D., Liu, P., and Cui, Y.: A literature review on characteristics of high temperature ferritic Cr–Mo steels and weldments, edited by C.D. Lundin (Welding Research Council, Inc., New York, WRC Bulletin 454, 2000).Google Scholar
5.Bhadeshia, H.K.D.H.: Design of ferritic creep-resistant steels. ISIJ Int. 41, 626 (2001).CrossRefGoogle Scholar
6.Knezevic, V., Sauthoff, G., Vilk, J., Inden, G., Schneider, A., Agamennone, R., Blum, W., Wang, Y., Scholz, A., Berger, C., Ehlers, J., and Singheiser, L.: Martensitic/ferritic super heat-resistant 650 °C steels: Design and testing of model alloys. ISIJ Int. 42, 1505 (2002).CrossRefGoogle Scholar
7.Fujita, T.: Heat-resistant steels for advanced power plants. Adv. Mater. Processes 141, 42 (1992).Google Scholar
8.Zhang, Z., Holloway, G.B., and Marshall, A.W.: Properties of T/P92 steel weld metals for ultra super critical (USC) power plant. Weld. World 52, 455 (2008).Google Scholar
9.Yoshizawa, M., Igarashi, M., Moriguchi, K., Iseda, A., Armaki, H.G., and Maruyama, K.: Effect of precipitates on long-term creep deformation properties of P92 and P122 type advanced ferritic steels for USC power plants. Mater. Sci. Eng., A 510–511, 162 (2009).CrossRefGoogle Scholar
10.Shinozaki, K., Dejun Li, H.K., Harada, H., Ohishi, K., and Sato, T.: Observation of type IV cracking in welded joints of high chromium ferritic heat resistant steels. Sci. Technol. Weld. Joining 8, 289 (2003).CrossRefGoogle Scholar
11.Francis, J.A., Mazur, W., and Bhadeshia, H.K.D.H.: Estimation of type IV cracking tendency in power plant steels. ISIJ Int. 44, 1966 (2004).CrossRefGoogle Scholar
12.Francis, J.A., Mazur, W., and Bhadeshia, H.K.D.H.: Type IV cracking in ferritic power plant steels. Mater. Sci. Technol. 22, 1387 (2006).CrossRefGoogle Scholar
13.Allen, D.J., Harvey, B., and Brett, S.J.: “FOURCRACK"–An investigation of the creep performance of advanced high alloy steel welds. Int. J. Press. Vessels Pip. 84, 104 (2006).CrossRefGoogle Scholar
14.Budden, P.J.: Analysis of the Type IV creep failures of three welded ferrictic pressures vessels. Int. J. Press. Vessels Pip. 75, 509 (1998).CrossRefGoogle Scholar
15.Komai, N. and Masuyama, F.: Microstructural degradation of the HAZ in 11Cr–0.4Mo–2W–V–Nb–Cu steel (P122) during creep. ISIJ Int. 42, 1364 (2002).CrossRefGoogle Scholar
16.Sawada, K., Tabuchi, M., Hongo, H., Watanabe, T., and Kimura, K.: Z-phase formation in welded joints of high chromium ferritic steels after long-term creep. Mater. Charact. 59, 1161 (2008).CrossRefGoogle Scholar
17.Li, Y., Hongo, H., Tabuchi, M., Takahashi, Y., and Monma, Y.: Evaluation of creep damage in heat affected zone of thick welded joint for Mod.9Cr–1Mo steel. Int. J. Press. Vessels Pip. 86, 585 (2009).CrossRefGoogle Scholar
18.Hald, J.: Microstructure and long-term creep properties of 9–12% Cr steels. Int. J. Press. Vessels Pip. 85, 30 (2008).CrossRefGoogle Scholar
19.Kim, B. and Lim, B.: Local creep evaluation of P92 steel weldment by small punch creep test. Acta. Mech. Solida Sin. 21, 312 (2008).CrossRefGoogle Scholar
20.Goods, S.H. and Brown, L.M.: Overview no. 1: The nucleation of cavities by plastic deformation. Acta Metall. 27, 1 (1979).CrossRefGoogle Scholar
21.Shinozaki, K., Li, D-J., Kuroki, H., Harada, H., and Ohishi, K.: Analysis of degradation of creep strength in heat-affected zone of weldment of high Cr heat-resisting steels based on void observation. ISIJ Int. 42, 1578 (2002).CrossRefGoogle Scholar
22.Ennis, P.J., Zielinska-Lipiec, A., Wachter, O., and Czyrska-Filemonowicz, A.: Microstructural stability and creep rupture strength of the martensitic steel P92 for advanced power plant. Acta Mater. 45, 4901 (1997).CrossRefGoogle Scholar
23.Pérez-Prado, M.T. and Kassner, M.E.: Fundamentals of Creep in Metals and Alloys. 2nd ed. (Elsevier, Amsterdam, The Netherlands, 2008), p. 95.CrossRefGoogle Scholar
24.Albert, S.K., Matsui, M., Hongo, H., Watanabe, T., Kubo, K., and Tabuchi, M.: Creep rupture properties of HAZs of a high Cr ferritic steel simulated by a weld simulator. Int. J. Press. Vessels Pip. 81, 221 (2004).CrossRefGoogle Scholar
25.Tezuka, H. and Sakurai, T.: A trigger of Type IV damage and a new heat treatment procedure to suppress it. Microstructural investigations of long-term ex-service Cr–Mo steel pipe elbows. Int. J. Press. Vessels Pip. 82, 165 (2005).CrossRefGoogle Scholar
26.Sugesawa, M., Sakurai, T., Aoki, M., and Fukushima, K.: Mechanism of creep damage in fine-grained heat affected zone of 2.25Cr–1Mo steel high temperature steam pipe (International Conference on Power Engineering, Shanghai, China, 1995), p. 1060.Google Scholar