Hardenability and Critical Average Cooling Rates of 7B50 Aluminum Alloy

IMR OpenIR

	Hardenability and Critical Average Cooling Rates of 7B50 Aluminum Alloy
	Kang Lei 1; Zhao Gang 1; Liu Kung 2; Tian Ni 1
	2019
发表期刊	RARE METAL MATERIALS AND ENGINEERING
ISSN	1002-185X
卷号	48 期号:1 页码:309-316
摘要	The hardenability and critical cooling rates of 7B50 alloy were investigated based on measured cooling curves obtained from the spray quenching test on modified Jominy specimen, electrical conductivity and hardness in different aging tempers, and microstructures evolution in natural aging temper. Results show that the hardened depth of 7B50 alloy is about 70 mm in natural aging temper while it decreases to 60 mm after natural aging for 50 d followed by artificial peak aging treatment with the corresponding average cooling rates in quench sensitive temperature range (420-230 degrees C) increasing from 1.55 degrees C.s(-1) to 1.95 degrees C.s(-1), indicating worse hardenability and more quench sensitivity after artificial peak aging treatment. During water-spray quenching, the precipitates form firstly on grain/subgrain boundaries and then at some special positions in matrix, such as Al3Zr particles. The inhomogeneous precipitates on grain/subgrain boundaries are observed at a location of 3 mm from the quenching surface with the corresponding average cooling rate of 981 degrees C.s(-1). While inhomogeneous precipitates in matrix are observed at a location of 10 mm from the quenching surface with the corresponding average cooling rate of 37.75 degrees C.s(-1). Properties of the alloy at 25 mm from the quenching surface have little changed compared with those on the quenching surface and the corresponding average cooling rate at the location of 25 mm is 9.34 degrees C.s(-1) which is much smaller than that on the quenching surface. Therefore, during the spray quenching process, the average cooling rate of 7B50 alloy thick plates should be controlled to be close to but not less than 9.34 degrees C.s(-1), in order to get excellent and uniform properties after quenching and aging.
关键词	QUENCH-SENSITIVITY MICROSTRUCTURE PRECIPITATION BEHAVIOR ZONES 7B50 aluminum alloy water-spray quenching hardenability cooling rate microstructure
收录类别	CSCD
语种	英语
CSCD记录号	CSCD:6412136
引用统计	被引频次：5[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/154863
专题	中国科学院金属研究所
作者单位	1.中国科学院金属研究所 2.University Quebec Chicoutimi, Chicoutimi, PQ G7H 2B1, Canada
推荐引用方式 GB/T 7714	Kang Lei,Zhao Gang,Liu Kung,et al. Hardenability and Critical Average Cooling Rates of 7B50 Aluminum Alloy[J]. RARE METAL MATERIALS AND ENGINEERING,2019,48(1):309-316.
APA	Kang Lei,Zhao Gang,Liu Kung,&Tian Ni.(2019).Hardenability and Critical Average Cooling Rates of 7B50 Aluminum Alloy.RARE METAL MATERIALS AND ENGINEERING,48(1),309-316.
MLA	Kang Lei,et al."Hardenability and Critical Average Cooling Rates of 7B50 Aluminum Alloy".RARE METAL MATERIALS AND ENGINEERING 48.1(2019):309-316.