The formation mechanism of characteristic region at crack initiation for very-high-cycle fatigue of high-strength steels

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	The formation mechanism of characteristic region at crack initiation for very-high-cycle fatigue of high-strength steels
	Hong YS(洪友士); Liu XL(刘小龙); Lei ZQ(雷铮强); Sun CQ(孙成奇)
	2016
会议名称	3rd International Conference on Characterisation of Crack Tip Fields
会议日期	APR 20-22, 2015
会议地点	Urbino, ITALY
关键词	Very-high-cycle fatigue Fatigue crack initiation Fine-granular-area Nanograins High-strength steels CHROMIUM-BEARING STEEL LONG-LIFE FATIGUE N-GREATER-THAN-10(7) CYCLES RESIDUAL-STRESSES VHCF-REGIME BEHAVIOR INCLUSIONS PROPAGATION DAMAGE SIZE
通讯作者	Hong, YS (reprint author), Chinese Acad Sci, Inst Mech, LNM, Beijing 100190, Peoples R China.
中文摘要	For high-strength steels, the crack initiation of very-high-cycle fatigue (VHCF) is commonly at the interior of material with fish-eye (FiE) morphology containing a fine-granular-area (FGA) surrounding an inclusion as crack origin, and FGA is regarded as the characteristic region of crack initiation. Here, we carefully examined the micro-morphology of FGA and FiE for two high-strength steels. The results revealed that the microscopic nature of FGA is a thin layer of nanograins. Then we proposed the formation mechanism of FGA: Numerous Cyclic Pressing (NCP) between originated crack surfaces, which causes grain refinement at originated crack wake and therefore the formation of FGA. The results of second set experiment showed that the cases with negative stress ratios exhibit the prevalence of nanograin layer in FGA region and the nanograin layer vanishes for the cases with positive stress ratios, which is a verification of the proposed NCP model. (C) 2015 Elsevier Ltd. All rights reserved.
收录类别	CPCI-S ; SCI ; EI
会议网址	10.1016/j.ijfatigue.2015.11.029
会议录	INTERNATIONAL JOURNAL OF FATIGUE
语种	英语
WOS记录号	WOS:000377839100012
内容类型	会议论文
源URL	[http://dspace.imech.ac.cn/handle/311007/60180]
专题	力学研究所_非线性力学国家重点实验室
推荐引用方式 GB/T 7714	Hong YS,Liu XL,Lei ZQ,et al. The formation mechanism of characteristic region at crack initiation for very-high-cycle fatigue of high-strength steels[C]. 见:3rd International Conference on Characterisation of Crack Tip Fields. Urbino, ITALY. APR 20-22, 2015.10.1016/j.ijfatigue.2015.11.029.