Microstructure evolution and mechanical properties of GH984G alloy with different Ti/Al ratios during long-term thermal exposure

IMR OpenIR

	Microstructure evolution and mechanical properties of GH984G alloy with different Ti/Al ratios during long-term thermal exposure
	T. T. Wang; C. S. Wang; W. Sun; X. Z. Qin; J. T. Guo; L. Z. Zhou
	2014
发表期刊	Materials & Design
ISSN	0261-3069
卷号	62 页码:225-232
摘要	GH984G alloy is a low cost Ni-Fe based wrought superalloy designed for 700 degrees C advanced ultra-supercritical (A-USC) coal-fired power plants. In this paper, the microstructure evolution and tensile properties of GH984G alloy with different Ti/Al ratios during thermal exposure at different high temperatures are investigated. Detailed microstructure analysis reveals that the Microstructure of alloys with different Ti/Al ratios are similar after standard heat treatment, and the primary precipitates are gamma', MC, M23C6 and M2B. However, eta phase precipitates at grain boundary in the alloy with high Ti/Al ratio after thermal exposure at 750 degrees C for 570 h. By contrast, the microstructure stability of the alloy with lower Ti/Al ratio is excellent. There is no detrimental phase even if after thermal exposure at 750 degrees C for 5000 h in the alloy with lower Ti/Al ratio. gamma' coarsening plays a great role on the tensile strength, and the critical size range of gamma' could be defined as approximately 27-40 nm. The influence of eta phase on tensile strength has close relationship with its volume fraction, the high volume fraction results in the decrease of tensile strength. The tensile strength of the alloy with lower Ti/Al ratio is obviously higher than the alloy with higher Ti/Al ratio and the yield strength has no obvious decrease during long-term thermal exposure at 700 degrees C. It is demonstrated that the thermal stability of microstructure and mechanical properties of GH984G alloy can be improved by moderately decreasing Ti/Al ratio to satisfy the requirement of A-USC plants. (C) 2014 Elsevier Ltd. All rights reserved.
部门归属	[wang, tingting ; wang, changshuai ; sun, wen ; qin, xuezhi ; guo, jianting ; zhou, lanzhang] chinese acad sci, inst met res, shenyang 110016, peoples r china. ; zhou, lz (reprint author), chinese acad sci, inst met res, shenyang 110016, peoples r china. ; lzz@imr.ac.cn
关键词	Ti/al Ratio Ni-fe Based Superalloy Microstructure Evolution Eta Phase Tensile Properties Eta-phase Boiler Materials Superalloy Stability Strength
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73423
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	T. T. Wang,C. S. Wang,W. Sun,et al. Microstructure evolution and mechanical properties of GH984G alloy with different Ti/Al ratios during long-term thermal exposure[J]. Materials & Design,2014,62:225-232.
APA	T. T. Wang,C. S. Wang,W. Sun,X. Z. Qin,J. T. Guo,&L. Z. Zhou.(2014).Microstructure evolution and mechanical properties of GH984G alloy with different Ti/Al ratios during long-term thermal exposure.Materials & Design,62,225-232.
MLA	T. T. Wang,et al."Microstructure evolution and mechanical properties of GH984G alloy with different Ti/Al ratios during long-term thermal exposure".Materials & Design 62(2014):225-232.