Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based alloy during long-term thermal exposure at 700 degrees C

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	Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based alloy during long-term thermal exposure at 700 degrees C
	Gao, Shuang; Hou, Jieshan; Yang, Fei; Guo, Yongan; Zhou, Lanzhang; Zhou, LZ (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China.
	2017-12-30
发表期刊	ELSEVIER SCIENCE SA
ISSN	0925-8388
卷号	729 页码:903-913
摘要	Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based superalloy, IN617B alloy, considered as a potential candidate for castings in 700 degrees C advanced ultra-supercritical (A-USC) coal-fired power plants, has been studied in this paper. Detailed observation reveals the alloys with different contents of Ta have similar solution treated microstructure. During long-term thermal exposure at 700 degrees C, Ta addition refines gamma' particles and enhances the thermal stability of gamma' phase by decreasing the gamma-gamma' lattice misfit. With increasing Ta content the solubility of Mo in matrix decreases, which promotes the transformation of film-like M23C6 at grain boundaries (GBs) into blocky M6C carbide with the reaction of M23C6 -> Mo--Cr(+Mo,Ta) M6C. Consequently, the morphology of GB carbide changes from continuous film structure to dispersed block structure. In addition, local concentration of metal elements leads to the precipitation of trace amount of s phase which is not affected by Ta concentration. Nearly all the tensile properties at 700 degrees C of the alloy after long-term thermal exposure are improved noticeably with the increase of Ta content. But, the plasticity of the alloy with 2.0 wt. % Ta addition decreases remarkably due to the excessive Ta content leading to severe M6C coarsening at GBs. The alloy achieves optimal mechanical properties with about 1.0 wt. % Ta content. (C) 2017 Elsevier B.V. All rights reserved.; Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based superalloy, IN617B alloy, considered as a potential candidate for castings in 700 degrees C advanced ultra-supercritical (A-USC) coal-fired power plants, has been studied in this paper. Detailed observation reveals the alloys with different contents of Ta have similar solution treated microstructure. During long-term thermal exposure at 700 degrees C, Ta addition refines gamma' particles and enhances the thermal stability of gamma' phase by decreasing the gamma-gamma' lattice misfit. With increasing Ta content the solubility of Mo in matrix decreases, which promotes the transformation of film-like M23C6 at grain boundaries (GBs) into blocky M6C carbide with the reaction of M23C6 -> Mo--Cr(+Mo,Ta) M6C. Consequently, the morphology of GB carbide changes from continuous film structure to dispersed block structure. In addition, local concentration of metal elements leads to the precipitation of trace amount of s phase which is not affected by Ta concentration. Nearly all the tensile properties at 700 degrees C of the alloy after long-term thermal exposure are improved noticeably with the increase of Ta content. But, the plasticity of the alloy with 2.0 wt. % Ta addition decreases remarkably due to the excessive Ta content leading to severe M6C coarsening at GBs. The alloy achieves optimal mechanical properties with about 1.0 wt. % Ta content. (C) 2017 Elsevier B.V. All rights reserved.
部门归属	[gao, shuang ; hou, jieshan ; yang, fei ; guo, yongan ; zhou, lanzhang] chinese acad sci, inst met res, shenyang 110016, liaoning, peoples r china ; [gao, shuang] univ chinese acad sci, beijing 100049, peoples r china
关键词	Ni-based Superalloy Microstructural Evolution Carbides Phase Transformation Mechanical Properties
学科领域	Chemistry, Physical ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	National Energy Administration Program of China [NY 20150102]; NSFC (National Natural Science Foundation of China [51571191]
收录类别	SCI
语种	英语
WOS记录号	WOS:000413555000111
引用统计	被引频次：51[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/78922
专题	中国科学院金属研究所
通讯作者	Zhou, LZ (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China.
推荐引用方式 GB/T 7714	Gao, Shuang,Hou, Jieshan,Yang, Fei,et al. Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based alloy during long-term thermal exposure at 700 degrees C[J]. ELSEVIER SCIENCE SA,2017,729:903-913.
APA	Gao, Shuang,Hou, Jieshan,Yang, Fei,Guo, Yongan,Zhou, Lanzhang,&Zhou, LZ .(2017).Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based alloy during long-term thermal exposure at 700 degrees C.ELSEVIER SCIENCE SA,729,903-913.
MLA	Gao, Shuang,et al."Effect of Ta on microstructural evolution and mechanical properties of a solid-solution strengthening cast Ni-based alloy during long-term thermal exposure at 700 degrees C".ELSEVIER SCIENCE SA 729(2017):903-913.