Investigation of fracture and determination of fracture toughness of modified 9Cr-1Mo steel weld metals using AE technique

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	Investigation of fracture and determination of fracture toughness of modified 9Cr-1Mo steel weld metals using AE technique
	X. Long; G. J. Cai; L. E. Svensson
	1999
发表期刊	Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
ISSN	0921-5093
卷号	270 期号:2 页码:260-266
摘要	Three-point bending test and acoustic emission technique are used to determine the fracture toughness and fracture process of three types of modified 9Cr-1Mo steel weld metals. Scanning electron microscopy is used to accomplish fractography analysis of fracture specimens. Microstructure of weld metals is investigated using optical microscopy and transmission electron microscopy. The fracture process and factors which affect fracture of the 9Cr-1Mo steel weld metals in post-weld heat treated condition are studied. Experimental results show that the modified 9Cr-1Mo steel weld metals fracture by a quasi-cleavage mechanism at ambient temperature. The microstructure of the weld metals is composed of mainly tempered martensite with M23C6 precipitates. In weld metals, microcracks nucleate from non-metallic inclusions. Fractures develop very quickly when cracks started to propagate. Comparatively, in weld metals with low strength, microcracks initiate at a low stress, but propagation of cracks is limited by plastic deformation. In weld metals with high strength, microcracks nucleate at high stresses, but cracks propagate very quickly and lead to almost immediate fracture of the specimens. As a result, weld metals with the low strength have a higher fracture toughness, while weld metals with higher strengths has a lower fracture toughness. (C) 1999 Elsevier Science S.A. All rights reserved.
部门归属	sw jiaotong univ, dept mat engn, chengdu 610031, peoples r china. chinese acad sci, inst met res, welding lab, shenyang 110015, peoples r china. esab ab, cent lab, s-41277 gothenburg, sweden.;cai, gj (reprint author), sw jiaotong univ, dept mat engn, chengdu 610031, peoples r china
关键词	9cr-1mo Steel Weld Metal Fracture Toughness Microstructure Acoustic Emission
URL	查看原文
WOS记录号	WOS:000083046500021
引用统计	被引频次：32[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/37436
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	X. Long,G. J. Cai,L. E. Svensson. Investigation of fracture and determination of fracture toughness of modified 9Cr-1Mo steel weld metals using AE technique[J]. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,1999,270(2):260-266.
APA	X. Long,G. J. Cai,&L. E. Svensson.(1999).Investigation of fracture and determination of fracture toughness of modified 9Cr-1Mo steel weld metals using AE technique.Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,270(2),260-266.
MLA	X. Long,et al."Investigation of fracture and determination of fracture toughness of modified 9Cr-1Mo steel weld metals using AE technique".Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing 270.2(1999):260-266.