Effect of Electron Beam Smelting Power on Microstructure, Segregation, and<i> γ</i> ′ Phase Precipitation Behavior of GH4068 Alloy

doi:10.11900/0412.1961.2023.00263

IMR OpenIR

	Effect of Electron Beam Smelting Power on Microstructure, Segregation, and γ ′ Phase Precipitation Behavior of GH4068 Alloy
	Bai, Rusheng 1,2; Tan, Yi 1,2; Cui, Hongyang 1,2; Ning, Lidan 1,2; Cui, Chuanyong 3; Wang, Yunpeng 1; Li, Pengting 1,2
通讯作者	Tan, Yi(lnsolar@dlut.edu.cn)
	2024-09-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	60 期号:9 页码:1189-1199
摘要	The as-cast structure of high-alloyed wrought superalloys exhibits disadvantages such as high microscopic segregation and poor microstructure uniformity, severely affecting their subsequent hot working and deformation properties. To optimize the as-cast structure of the wrought superalloy, GH4068 alloy was smelted via electron beam smelting (EBS), and its ingots with low segregation were prepared by setting different EBS powers for 10 min. The results show that the bottom of the ingots after EBS appeared to be fine grain regions, with the presence of only cellular segregation structure and cellular dendritic crystal; the large area in the middle became vertically growing columnar crystal regions, the direction of secondary dendrite crystal growth was parallel to that of the columnar crystal growth; a small amount of equiaxed crystal was observed at the top, and the growth direction of dendritic crystals was disordered. Analyzing the compositions of ingots revealed that Cr volatilization in this alloy was the most obvious; the Cr content decreased by 1.97% when the EBS power was 17 kW. The ingot structure prepared via EBS was more highly distributed than that obtained using the traditional vacuum induction melting + electroslag remelting duplex process. When the EBS power was 12 kW, the secondary dendrite spacing lambda 2 was 44.6 mu m, which was 32.2% less than that yielded using the duplex process, the degree of the microscopic segregation of the ingot dendrite region decreased considerably, and the degree of the microscopic segregation of the typical easily segregated elements Ti and W reduced by 20.4% and 18.6%, respectively. Furthermore, the massive precipitation of large interdendritic gamma ' phases were observed, while the gamma ' phases in the dendritic core were spherical and smaller in size than those in the interdendritic. Meanwhile, the ingot prepared with an EBS power of 12 kW achieved the smallest size for gamma ' phases and least irregular gamma ' phases in the interdendritic. In the EBS process, the actual melt temperature was considerably higher than the alloy melting temperature. After the overheating of the melt, the cluster structure effectively decomposed, elements were uniformly distributed, the degree of subcooling increased in the solidification process, and the uniformity of the melt was inherited to the solidification structure to refine the as-cast structure and reduce the degree of microscopic segregation. Meanwhile, during the EBS process, local high temperature generated due to the electron beam bombardment on the surface of the molten pool effectively reduced the N content in the alloy.
关键词	electron beam smelting superalloy dendritic structure microscopic segregation
资助者	National Key Research and Development Program of China
DOI	10.11900/0412.1961.2023.00263
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2019YFA0705300]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:001320333900004
出版者	SCIENCE PRESS
引用统计	被引频次：3[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/321006/191617
专题	中国科学院金属研究所
通讯作者	Tan, Yi
作者单位	1.Dalian Univ Technol, Sch Mat Sci & Engn, Dalian 116024, Peoples R China 2.Dalian Univ Technol, Key Lab Energy Beam Met & Adv Mat Preparat Liaonin, Dalian 116024, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shi Changxu Innovat Ctr Adv Mat, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Bai, Rusheng,Tan, Yi,Cui, Hongyang,等. Effect of Electron Beam Smelting Power on Microstructure, Segregation, and γ ′ Phase Precipitation Behavior of GH4068 Alloy[J]. ACTA METALLURGICA SINICA,2024,60(9):1189-1199.
APA	Bai, Rusheng.,Tan, Yi.,Cui, Hongyang.,Ning, Lidan.,Cui, Chuanyong.,...&Li, Pengting.(2024).Effect of Electron Beam Smelting Power on Microstructure, Segregation, and γ ′ Phase Precipitation Behavior of GH4068 Alloy.ACTA METALLURGICA SINICA,60(9),1189-1199.
MLA	Bai, Rusheng,et al."Effect of Electron Beam Smelting Power on Microstructure, Segregation, and γ ′ Phase Precipitation Behavior of GH4068 Alloy".ACTA METALLURGICA SINICA 60.9(2024):1189-1199.