Improved nitrogen transport in steels during surface nanocrystallized low-carbon gaseous nitridation

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	Improved nitrogen transport in steels during surface nanocrystallized low-carbon gaseous nitridation
	Gu, JF ; Bei, DH ; Pan, JS ; Lu, J ; Lu, K
刊名	MATERIALS LETTERS
	2002-08-01
卷号	55 期号:5 页码:340-343
关键词	gaseous nitridation growth reactivity diffusion nanostructure ultrasonic shot peening (USSP) surface nanocrystallization
ISSN号	0167-577X
通讯作者	Gu, JF()
英文摘要	In the thermochemical process of low carbon steel nitridation improvements of mechanical properties are governed by the nature (hardness thickness etc) of the compound layer since the compound layer will be kept under working conditions. Because of low nitrogen diffusivity m steel and low mass transfer between gaseous reaction and steel long duration and high temperature are classically used for thermal nitridation. The present study shows that improved nitrogen transport can be obtained by gaseous nitridation after the samples have been surface nanocrystallized by ultrasonic shot peening (USSP). Comparing to the untreated samples the nitridation efficiency of treated samples has been improved dramatically. The growth of gamma nitride layer conforms to a parabolic relationship with nitridation duration during the whole nitridation process in treated samples while in untreated samples the growth of nitride layer could be traditionally divided into two stages the first linear growth stage and the second parabolic growth stage. This difference clearly indicated that the whole nitridation process is diffusion controlled in treated samples instead of interface reaction controlled stage and then diffusion controlled stage in untreated samples. The high nitridation efficiency obtained may be explained by an increased volume fraction of grain boundary and an enhanced reactivity of surface atoms of the steel samples due to the nanostructure layer generated by surface nanocrystallization of USSP. (C) 2002 Elsevier Science B.V. All rights reserved.
WOS研究方向	Materials Science ; Physics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000177740900012
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/115457]
专题	金属研究所_中国科学院金属研究所
通讯作者	Gu, JF
作者单位	1.Univ Technol Troyes, LASMIS, F-10010 Troyes, France 2.Shanghai Jiao Tong Univ, Key lab High Temp Mat & Tests, Educ Mininst, Shanghai 200030, Peoples R China 3.Chinese Acad Sci, State Key Lab RSA, Met Res Inst, Shenyang 110015, Peoples R China
推荐引用方式 GB/T 7714	Gu, JF,Bei, DH,Pan, JS,et al. Improved nitrogen transport in steels during surface nanocrystallized low-carbon gaseous nitridation[J]. MATERIALS LETTERS,2002,55(5):340-343.
APA	Gu, JF,Bei, DH,Pan, JS,Lu, J,&Lu, K.(2002).Improved nitrogen transport in steels during surface nanocrystallized low-carbon gaseous nitridation.MATERIALS LETTERS,55(5),340-343.
MLA	Gu, JF,et al."Improved nitrogen transport in steels during surface nanocrystallized low-carbon gaseous nitridation".MATERIALS LETTERS 55.5(2002):340-343.