Microstructures and intermediate temperature brittleness of newly developed Ni-Fe based weld metal for ultra-supercritical power plants

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	Microstructures and intermediate temperature brittleness of newly developed Ni-Fe based weld metal for ultra-supercritical power plants
	Wu, Dong; Li, Dianzhong; Lu, Shanping; Lu, SP (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.
	2017-01-27
发表期刊	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN	0921-5093
卷号	684 页码:146-157
摘要	Temperature dependent tensile behavior of Ni-Fe based weld metal by gas tungsten arc welding (GTAW) was evaluated in the range of 350-820 degrees C at a strain rate of 0.035/min. Intergranular fracture and intermediate temperature brittleness (ITB) took place at around 750 degrees C. The microstructure and the fracture surface morphology observation by optical microscopy, scanning and transmission electron microscopy showed that the ITB to a large extent depended on the grain boundary sliding (GBS) and the gamma prime (gamma') precipitation during the elevated temperature tensile deformation. X-ray diffraction (XRD) confirmed that the primary phases formed during the last stage of solidification were mainly TiN nitrides, MC carbides, and Laves phases in the form of Laves/gamma eutectics. Quantitative statistics of the Laves/gamma eutectics and the MX(MC, TiN) phases were processed. These primary phases had a pinning effect on the migration of grain boundaries and accordingly made the grain boundaries tortuous. The tortuous grain boundaries were expected to inhibit the GBS, relieving ITB. Transmission electron microscopy confirmed that fine Laves particles precipitated along the grain boundary in the weld metal with higher Mo content during the deformation process, and these Laves particles were also supposed to be one factor for inhibiting the GBS.; Temperature dependent tensile behavior of Ni-Fe based weld metal by gas tungsten arc welding (GTAW) was evaluated in the range of 350-820 degrees C at a strain rate of 0.035/min. Intergranular fracture and intermediate temperature brittleness (ITB) took place at around 750 degrees C. The microstructure and the fracture surface morphology observation by optical microscopy, scanning and transmission electron microscopy showed that the ITB to a large extent depended on the grain boundary sliding (GBS) and the gamma prime (gamma') precipitation during the elevated temperature tensile deformation. X-ray diffraction (XRD) confirmed that the primary phases formed during the last stage of solidification were mainly TiN nitrides, MC carbides, and Laves phases in the form of Laves/gamma eutectics. Quantitative statistics of the Laves/gamma eutectics and the MX(MC, TiN) phases were processed. These primary phases had a pinning effect on the migration of grain boundaries and accordingly made the grain boundaries tortuous. The tortuous grain boundaries were expected to inhibit the GBS, relieving ITB. Transmission electron microscopy confirmed that fine Laves particles precipitated along the grain boundary in the weld metal with higher Mo content during the deformation process, and these Laves particles were also supposed to be one factor for inhibiting the GBS.
部门归属	[wu, dong ; li, dianzhong ; lu, shanping] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china
关键词	Ni-fe Based Superalloy Weld Metal Tensile Deformation Grain Boundary Sliding Tortuous Grain Boundary
学科领域	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	National High Technology Research and Development Program [2012AA03A501]
收录类别	SCI
语种	英语
WOS记录号	WOS:000393938300018
引用统计	被引频次：16[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/321006/78329
专题	中国科学院金属研究所
通讯作者	Lu, SP (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.
推荐引用方式 GB/T 7714	Wu, Dong,Li, Dianzhong,Lu, Shanping,et al. Microstructures and intermediate temperature brittleness of newly developed Ni-Fe based weld metal for ultra-supercritical power plants[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2017,684:146-157.
APA	Wu, Dong,Li, Dianzhong,Lu, Shanping,&Lu, SP .(2017).Microstructures and intermediate temperature brittleness of newly developed Ni-Fe based weld metal for ultra-supercritical power plants.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,684,146-157.
MLA	Wu, Dong,et al."Microstructures and intermediate temperature brittleness of newly developed Ni-Fe based weld metal for ultra-supercritical power plants".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 684(2017):146-157.