Micromechanism of Cleavage Fracture ofWeld Metals

doi:10.11900/0412.1961.2017.00145

	Micromechanism of Cleavage Fracture ofWeld Metals
	Chen Jianhong1,2 ; Cao Rui1,2
	2017-11-11
发表期刊	Jinshu Xuebao/Acta Metallurgica Sinica
ISSN	04121961
卷号	53 期号:11 页码:1427-1444
摘要	Cleavage fracture is the most dangerous form of fracture. Cleavage fracture usually happens well before general yielding at low nominal fracture stress and strain. Cleavage fracture is often spurred by low temperature and determines the toughness in the lower shelf temperature region. This paper describes a new framework for the micromechanism of cleavage fracture of high strength low alloy (HSLA) steel weld metals. Cleavage fracture not only determines the impact toughness in the lower shelf but also plays a decisive role on the impact toughness in the transition temperature region. The toughness is determined by the extending length of a preceding fibrous crack which is terminated by cleavage fracture. Three non-stop successive stages, i.e. crack nucleation, propagation of a second phase particlesized crack across the particle/grain boundary, propagation of a grain-sized crack across the grain/grain boundary are explained. The "critical event" of cleavage fracture is emphasized which offers the greatest difficulty during crack formation and controls the cleavage process. The critical event indicates the weakest microstructural component and its critical size which specifies the local cleavage fracture stress sf for cleavage fracture. In toughness-study it is paramount important to reveal the critical events for various test specimens. Three criteria for crack nucleation, for preventing crack nucleus from blunting and for crack propagation are testified. An active region specified by these criteria is suggested where the combined stress and strain are sufficient to trigger the cleavage fracture. It can be used in statistical analyses. A case study, using the new framework of micromechanism for analyzing toughness of 8%Ni steel welding metals is presented to analyze the experimental results. © All right reserved.
关键词	Crystallization Fracture Fracture toughness High strength alloys High-strength low-alloy steel Nickel steel Nucleation Particle size analysis Temperature Cleavage fracture Critical events Fracture criteria Fracture process Grain-sized crack High strength low alloys Micro mechanisms Temperature regions
DOI	10.11900/0412.1961.2017.00145
收录类别	EI ; SCIE
语种	中文
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000416301500003
出版者	Chinese Academy of Sciences
EI入藏号	20180604756328
EI主题词	Cracks
EI分类号	531.1 Metallurgy - 641.1 Thermodynamics - 802.3 Chemical Operations - 933.1.2 Crystal Growth - 951 Materials Science
来源库	Compendex
分类代码	531.1 Metallurgy - 641.1 Thermodynamics - 802.3 Chemical Operations - 933.1.2 Crystal Growth - 951 Materials Science
引用统计	被引频次：8[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	https://ir.lut.edu.cn/handle/2XXMBERH/114403
专题	材料科学与工程学院_特聘教授组材料科学与工程学院
通讯作者	Chen Jianhong
作者单位	1.Lanzhou Univ Technol, Dept Mat Sci & Engn, State Key Lab Adv Proc & Recycling Nonferrous Met, Lanzhou 730050, Gansu, Peoples R China; 2.Lanzhou Univ Technol, Dept Mat Sci & Engn, Lanzhou 730050, Gansu, Peoples R China
第一作者单位	兰州理工大学
通讯作者单位	兰州理工大学
第一作者的第一单位	兰州理工大学
推荐引用方式 GB/T 7714	Chen Jianhong,Cao Rui. Micromechanism of Cleavage Fracture ofWeld Metals[J]. Jinshu Xuebao/Acta Metallurgica Sinica,2017,53(11):1427-1444.
APA	Chen Jianhong,&Cao Rui.(2017).Micromechanism of Cleavage Fracture ofWeld Metals.Jinshu Xuebao/Acta Metallurgica Sinica,53(11),1427-1444.
MLA	Chen Jianhong,et al."Micromechanism of Cleavage Fracture ofWeld Metals".Jinshu Xuebao/Acta Metallurgica Sinica 53.11(2017):1427-1444.