Precipitation Behavior of delta Phase of Deformation Induced GH3625 Superalloy Hot-Extruded Tube

doi:10.11900/0412.1961.2016.00508

	Precipitation Behavior of delta Phase of Deformation Induced GH3625 Superalloy Hot-Extruded Tube
	Ding Yutian; Gao Yubi; Dou Zhengyi; Gao Xin; Liu Dexue; Jia Zhi
刊名	ACTA METALLURGICA SINICA
	2017-06
卷号	53 期号:6 页码:695-702
关键词	GH3625 superalloy cold deformation delta phase precipitation behavior kinetics
ISSN号	0412-1961
DOI	10.11900/0412.1961.2016.00508
英文摘要	GH3625 alloy is a wrought nickel-based superalloy mainly used in aeronautical, aerospace, chemical, nuclear, petrochemical, and marine applications industry due to its good mechanical properties, processability, weldability and resistance to high-temperature corrosion on prolonged exposure to aggressive environments. However, in medium and high temperature environment during long-term service, the gamma" is a metastable phase, easily transformed into stable delta phase, or d phase directly formed in the gamma matrix so that alloy performance was deteriorated, leading to the result of alloy failure. At the present work, mass fraction of d phase in GH3625 superalloy hot-extruded tube cold deformed to different reductions and then aged at 800 degrees C for different times, were measured by XRD. The effect of cold deformation on the law and kinetics of d phase precipitation was investigated by SEM, EDS and Image-Pro Plus metallographic analysis. The results show that d phase first precipitates at the deformation twin and grain boundaries as well as deformation bands, and then precipitates in the grains. The amount of delta phase at the deformation bands increases with the increase of cold deformation. The morphologies of delta phase change gradually from needles to spheroids or rodlike with increasing cold deformation. With the extend of ageing time, the average size of delta phase increases which grows according to LSW theory. At 800 degrees C, the relationship between the precipitation content of delta phase and ageing time follows Avrami equation. As cold deformation increases, the content of delta phase increases, the time index n decreases, whereas the d phase precipitation rate increases. Cold deformation promotes the precipitation of delta phase. The solute drags of Nb in soild solution and pinning of delta phase inhibits the grain growth during ageing process of cold deformed GH3625 superalloy hot-extruded tube. The hardness of the alloy increases with the extension of the holding time at epsilon = 35% but no obvious change at epsilon >= 50%.
资助项目	National Natural Science Foundation of China[51661019] ; Science and Technology Project of Gansu Province[145RTSA004]
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000405561500007
状态	已发表
内容类型	期刊论文
源URL	[http://119.78.100.223/handle/2XXMBERH/33248]
专题	材料科学与工程学院省部共建有色金属先进加工与再利用国家重点实验室
通讯作者	Ding Yutian
作者单位	Lanzhou Univ Technol, State Key Lab Adv Proc & Recycling Nonferrous Met, Lanzhou 730050, Peoples R China
推荐引用方式 GB/T 7714	Ding Yutian,Gao Yubi,Dou Zhengyi,et al. Precipitation Behavior of delta Phase of Deformation Induced GH3625 Superalloy Hot-Extruded Tube[J]. ACTA METALLURGICA SINICA,2017,53(6):695-702.
APA	Ding Yutian,Gao Yubi,Dou Zhengyi,Gao Xin,Liu Dexue,&Jia Zhi.(2017).Precipitation Behavior of delta Phase of Deformation Induced GH3625 Superalloy Hot-Extruded Tube.ACTA METALLURGICA SINICA,53(6),695-702.
MLA	Ding Yutian,et al."Precipitation Behavior of delta Phase of Deformation Induced GH3625 Superalloy Hot-Extruded Tube".ACTA METALLURGICA SINICA 53.6(2017):695-702.