Microstructural evolution and mechanical property of a Ni-Fe-based weld metal during long-term exposure at 650 degrees C and 700 degrees C

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	Microstructural evolution and mechanical property of a Ni-Fe-based weld metal during long-term exposure at 650 degrees C and 700 degrees C
	Wu, D; Li, DZ; Lu, SP; Lu, SP (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Beijing, Peoples R China.
刊名	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
	2018-02-14
卷号	716 页码:240-251
关键词	Thermal Exposure Power-plants Electron-microscopy Coarsening Behavior Tensile Properties Ti/al Ratios Superalloy Alloy Stability Precipitation
ISSN号	0921-5093
英文摘要	A newly developed Ni-Fe-based weld metal has been researched for the microstructural and mechanical evolutions during prolonged thermal exposure using scanning electron microscopy and transmission electron microscopy. The M23C6-carbides precipitated at grain boundaries and around the primary (Nb, Ti)C phases in the Ni-Fe-based weld metal during prolonged exposure at 650 degrees C and 700 degrees C. The Cr, Mo-rich sigma(sigma) and Cr-rich alpha-Cr formed as platelets and mainly located in the interdendritic areas during the exposure. sigma phase had the orientation relationships of [001](gamma)//[11 (2) over bar](sigma), ((2) over bar 20)(gamma)//((1) over bar 10)(sigma) and ((2) over bar(2) over bar0)(gamma)//(111)(sigma), with the gamma matrix. Higher (Al + Ti) content accelerated the precipitation of these Cr-rich phases and resulted in a significant deterioration of tensile ductility after 5000 h at 700 degrees C. Precipitating and coarsening of spherical gamma' dominated the tensile strength evolution and the optimized gamma' radius with the best tensile strength was estimated to be 21-25 nm. (Al + Ti) content had no obvious effect on the gamma' coarsening rate but it affected the gamma' particle density N, in two sides: On the one hand, higher (Al + Ti) content increased the N-s, which increased the 0.2% yield strength (R-p0.2)and tensile strength (R-m). On the other hand, higher (Al + Ti) content increased the amount of sigma phases which induced the gamma' envelopes to form and resulted in the decrease of N-s, and it would decreased the R-p0.2 and R-m.; A newly developed Ni-Fe-based weld metal has been researched for the microstructural and mechanical evolutions during prolonged thermal exposure using scanning electron microscopy and transmission electron microscopy. The M23C6-carbides precipitated at grain boundaries and around the primary (Nb, Ti)C phases in the Ni-Fe-based weld metal during prolonged exposure at 650 degrees C and 700 degrees C. The Cr, Mo-rich sigma(sigma) and Cr-rich alpha-Cr formed as platelets and mainly located in the interdendritic areas during the exposure. sigma phase had the orientation relationships of [001](gamma)//[11 (2) over bar](sigma), ((2) over bar 20)(gamma)//((1) over bar 10)(sigma) and ((2) over bar(2) over bar0)(gamma)//(111)(sigma), with the gamma matrix. Higher (Al + Ti) content accelerated the precipitation of these Cr-rich phases and resulted in a significant deterioration of tensile ductility after 5000 h at 700 degrees C. Precipitating and coarsening of spherical gamma' dominated the tensile strength evolution and the optimized gamma' radius with the best tensile strength was estimated to be 21-25 nm. (Al + Ti) content had no obvious effect on the gamma' coarsening rate but it affected the gamma' particle density N, in two sides: On the one hand, higher (Al + Ti) content increased the N-s, which increased the 0.2% yield strength (R-p0.2)and tensile strength (R-m). On the other hand, higher (Al + Ti) content increased the amount of sigma phases which induced the gamma' envelopes to form and resulted in the decrease of N-s, and it would decreased the R-p0.2 and R-m.
学科主题	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
语种	英语
资助机构	National High Technology Research and Development Program [2012AA03A501]
公开日期	2018-06-05
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79503]
专题	金属研究所_中国科学院金属研究所
通讯作者	Lu, SP (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Beijing, Peoples R China.
推荐引用方式 GB/T 7714	Wu, D,Li, DZ,Lu, SP,et al. Microstructural evolution and mechanical property of a Ni-Fe-based weld metal during long-term exposure at 650 degrees C and 700 degrees C[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2018,716:240-251.
APA	Wu, D,Li, DZ,Lu, SP,&Lu, SP .(2018).Microstructural evolution and mechanical property of a Ni-Fe-based weld metal during long-term exposure at 650 degrees C and 700 degrees C.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,716,240-251.
MLA	Wu, D,et al."Microstructural evolution and mechanical property of a Ni-Fe-based weld metal during long-term exposure at 650 degrees C and 700 degrees C".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 716(2018):240-251.