Effect of Boron Content on Microstructure Evolution During Solidification and Mechanical Properties of K417G Alloy

doi:10.11900/0412.1961.2018.00491

CORC > 金属研究所 > 中国科学院金属研究所

	Effect of Boron Content on Microstructure Evolution During Solidification and Mechanical Properties of K417G Alloy
	Liu Qiaomu 1; Huang Shunzhou 1; Liu Fang 2; Yang Yan 3; Nan Hongqiang 3; Zhang Dong 3; Sun Wenru 2
刊名	ACTA METALLURGICA SINICA
	2019-06-11
卷号	55 期号:6 页码:720-728
关键词	K417G alloy B solidification process microstructure mechanical property
ISSN号	0412-1961
DOI	10.11900/0412.1961.2018.00491
通讯作者	Sun Wenru(wrsun@imr.ac.cn)
英文摘要	Boron is a key element in superalloys and many other metallic materials for strengthening the grain boundaries. However, it also has harmful effect on aggravating the solidification segregation of the alloys. Although the mechanism for the influences of B on the alloys has been studied extensively, it is still required to study in some alloys currently because the compositive effects of boron in different alloys are sometimes distinct. K417G, a cast superalloy with good comprehensive properties, has been applied in aero engines of China. In the present work, the effects of boron content on the microstructure evolution during the solidification and the mechanical properties of the as cast K417G alloy have been investigated, providing some fundamental information for the control of boron addition in the alloy. It has been found that boron aggravated the elemental segregation and promoted the eutectic (gamma+gamma') precipitation at the final stage of the solidification of K417G alloy. In addition, boron decreased the precipitation temperature, and hence reduced the nucleation rate of the gamma matrix. When the boron content was below 0.036%, the grain size was increased with the increment of B content, which is caused by the decreased nucleation of the gamma phase. When the B addition was increased up to 0.060%, the grain was refined at some local places, because the growth of the dendrites was inhibited and the gamma phase could nucleate at the inner part of the subcooled liquids. The mechanical properties of K417G alloy were significantly influenced by the precipitation of the boride at the grain boundaries. The borides were precipitated as fine particles at the grain boundaries when the B addition was below 0.036%, and the tensile properties at 900 degrees C and the stress rupture properties at 900 degrees C and 315 MPa were markedly improved with the increasing B content in this addition range. When the B content was increased to 0.060%, the boride was precipitated as eutectic form in front of the eutectic (gamma+gamma'). The tensile and stress rupture properties were decreased due to the weak cohesion between the eutectic (gamma+gamma') and the eutectic form borides.
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000468415300005
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/133506]
专题	金属研究所_中国科学院金属研究所
通讯作者	Sun Wenru
作者单位	1.AECC Sichuan Gas Turbine Estab, Chengdu 610500, Sichuan, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China 3.Jinchuan Grp Co Ltd, Lab Nickel & Cobalt Resources Comprehens Utilizat, Jinchang 737100, Peoples R China
推荐引用方式 GB/T 7714	Liu Qiaomu,Huang Shunzhou,Liu Fang,et al. Effect of Boron Content on Microstructure Evolution During Solidification and Mechanical Properties of K417G Alloy[J]. ACTA METALLURGICA SINICA,2019,55(6):720-728.
APA	Liu Qiaomu.,Huang Shunzhou.,Liu Fang.,Yang Yan.,Nan Hongqiang.,...&Sun Wenru.(2019).Effect of Boron Content on Microstructure Evolution During Solidification and Mechanical Properties of K417G Alloy.ACTA METALLURGICA SINICA,55(6),720-728.
MLA	Liu Qiaomu,et al."Effect of Boron Content on Microstructure Evolution During Solidification and Mechanical Properties of K417G Alloy".ACTA METALLURGICA SINICA 55.6(2019):720-728.