EVOLUTION BEHAVIOR OF LAVES PHASE IN FB2 MARTENSITIC STAINLESS STEEL DURING WELDING

doi:10.11900/0412.1961.2015.00590

Acta Metall Sin

2016, Vol. 52

Issue (6): 641-648 DOI: 10.11900/0412.1961.2015.00590

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EVOLUTION BEHAVIOR OF LAVES PHASE IN FB2 MARTENSITIC STAINLESS STEEL DURING WELDING

Kejian LI¹,Zhipeng CAI^1,^2,³(

),Yifei LI¹,Jiluan PAN¹

1 Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China .
2 State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
3 Collabrative Innovation Center of Advanced Nuclear Energy Technology, Tsinghua University, Beijing 100084, China

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Kejian LI,Zhipeng CAI,Yifei LI,Jiluan PAN. EVOLUTION BEHAVIOR OF LAVES PHASE IN FB2 MARTENSITIC STAINLESS STEEL DURING WELDING. Acta Metall Sin, 2016, 52(6): 641-648.

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Abstract

Elevating steam parameters is the key to enhance the efficiency of fossil power plants, reducing fuel consumption and noxious emission. Therefore, a lot of new creep resistant martensitic stainless steels have been developed, among which FB2 steel (a new 9%Cr martensitic stainless steel) is the most promising candidate for manufacturing steam turbine rotors operated at temperature range from 600 ℃ to 650 ℃. In the present work, the evolution behavior of Laves phase in the as received FB2 steel was studied by thermal simulation technique. Firstly, some sparse micron-sized particles of Laves phase were observed in as received FB2 steel by SEM. It was concluded that the large Laves phase particles formed in casting due to dendritic segregation. Then constitutional liquation resulting from eutectic reaction between Laves phase and γ-Fe in the heating process of welding thermal simulation was found, suggesting a liquation crack tendency in heat affected zone of FB2 steel. In the specimens experiencing thermal simulation, some eutectic microstructures were observed by SEM. Based on the results of EDS analysis and SAED, the two eutectic constituents were identified as χ phase and γ-Fe. At last, the reason for the difference in morphology of eutectic microstructures between specimens experiencing thermal simulation with different peak temperatures was analyzed.

Key words: FB2 steel Laves phase constitutional liquation χ phase hot crack tendency welding

Received: 16 November 2015

Fund: Supported by Shanghai Science and Technology Committee (No.13DZ1101500) and Tribology Science Fund of State Key Laboratory of Tribology of Tsinghua University (No.SKLT2015A02)

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https://www.ams.org.cn/EN/10.11900/0412.1961.2015.00590 OR https://www.ams.org.cn/EN/Y2016/V52/I6/641

Fig.1 Process of preparing the TEM specimen of eutectic microstructure by focused ion beam (FIB), sequence is (a~f)

Fig.2 SEM-SE image (a) and EDS result (b) of Laves phases (arrows) in FB2 steel in as received condition

Fig.3 SEM images of Laves phase in specimens and EDS analysis results (insets) after thermal simulation at peak temperature 1150 ℃ (a) and 1200 ℃ (b)

Fig.4 SEM images of specimen experiencing peak temperature of 1250 ℃

(a) discontinuous band of microstructure, some of which presents eutectic morphology (Arrows show the discontinuous eutectic microstructures and inset shows the highly magnified image)

(b) discretely distributed eutectic microstructures (Arrows show particles surrounding the netlike microstructures and inset shows EDS analysis result)

Fig.5 SEM images of specimen experiencing peak temperature of 1350 ℃

(a) continuous eutectic microstructure (Inset shows the highly magnified image, and arrows show the strip shaped microstructures at grain boundaries)

(b) micro topography of eutectic microstructure (Inset shows the EDS analysis result of eutectic microstructures, and arrows show the strip shaped microstructures at grain boundaries)

Fig.6 Equilibrium solidification path of the netlike eutectic constituent and II in Fig.7a

Fig.7 TEM results of eutectic microstructure in specimen experiencing thermal simulation with peak temperature of 1350 ℃ (a) bright field TEM image of eutectic microstructure (Arrows 1~5 show the netlike eutectic constituent and arrows I~IV show the other eutectic constituent inside the net mesh) (b) SAED patterns of points 1, 2, I

Table 1 Comparison of chemical composition of χ phase in references and the eutectic constituent in this work (mass fraction / %)

[1]	Sun R, Cui Z Z, Tao Y.In: Gandy D, Shingledecker J eds., Advances in Materials Technology for Fossil Power Plants Proceedings from the Seventh International Conference, Novelty, Ohio: ASM International, 2014: 1
[2]	Di Gianfrancesco A, Tizzanini A, Jedamzik M, Stolzenberger C.In: Gandy D, Shingledecker J eds., Advances in Materials Technology for Fossil Power Plants Proceedings from the Seventh International Conference, Novelty, Ohio: ASM International, 2014: 9
[3]	Fukuda M, Saito E, Semba H, Iwasaki J, Izumi S, Takano S, Takahashi T, Sumiyoshi Y.In: Grandy D, Shingledecker J eds., Advances in Materials Technology for Fossil Power Plants Proceedings from the Seventh International Conference, Novelty, Ohio: ASM International, 2014: 24
[4]	Jara D R.PhD Dissertation, Ruhr University Bochum, 2011
[5]	Mayr P.PhD Dissertation, Graz University of Technology, 2007
[6]	Di Gianfrancesco A, Budano S, Lombardi P, Paura M, Neri S, Calderini M, Longari N.In: Gandy D, Shingledecker J eds., Advances in Materials Technology for Fossil Power Plants Proceedings from the Seventh International Conference, Novelty, Ohio: ASM International, 2014: 304
[7]	Blaes N, Donth B, Bokelmann D.Energy Mater, 2007; 2(4): 207
[8]	Azuma T, Miki K, Tanaka Y, Isshiguro T.Tetsu Hagané, 2002; 88: 678
[8]	(東司, 三木一宏, 田中泰彦, 石黒徹.鉄と鋼, 2002; 88: 678)
[9]	Horiuchi T, Igarashi M, Abe F.ISIJ Int, 2002; 42(suppl): S67
[10]	Shige T, Magoshi R, Itou S, Ichimura T, Kondou Y.Mitsubishi Heavy Industry Tech Rev, 2001; 38(1): 6
[11]	Dzugan J, Novy Z, Konopik P, Podany P.In: Gandy D, Shingledecker J eds., Advances in Materials Technology for Fossil Power Plants Proceedings from the Seventh International Conference, Novelty, Ohio: ASM International, 2014: 924
[12]	Xu Y T, Wang M J, Wang Y, Gu T, Chen L, Zhou X, Ma Q, Liu Y M, Huang J.J Alloys Compd, 2015; 621: 93
[13]	Dimmler G, Weinert P, Kozeschnik E, Cerjak H.Mater Charact, 2003; 51: 341
[14]	Cui H R, Sun F, Chen K, Zhang L T, Wan R C, Shan A D, Wu J S.Mater Sci Eng, 2010; A527: 7505
[15]	Korcakova L, Hald J, Somers M.Mater Charact, 2001; 47: 111
[16]	Jandová D, Kasl J, Chvostová E.Mater Sci Forum, 2014; 782: 311
[17]	Kasl J, Jandová D.Mater Sci Forum, 2014; 782: 179
[18]	Brooks J A.Weld J, 1974; 53(suppl): S517
[19]	Ying H Y, Shi C G, Hao C Y, Yu E J, Qin X D, Zhang Q.Acta Metall Sin, 1997; 33: 995
[19]	(应慧筠, 施成根, 郝传勇, 于尔靖, 秦旭东, 张琪. 金属学报, 1997; 33: 995)
[20]	Vagi J J, Martin D C.Weld J, 1956; 35(suppl 3): 137s
[21]	Kasper J S.Acta Metall, 1954; 2: 456
[22]	Cieslak M J, Ritter A M, Savage W F.Weld J, 1984; 63: 133
[23]	Kautz H R, Gerlach H.Arch Eisenhuttenw, 1968; 39: 151
[24]	Omsen A, Eliasson L.ISIJ Int, 1971; 209: 830
[25]	Weiss B, Stickler R.Metall Trans, 1972; 3A: 851

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