Microstructure and Impact Toughness of Welding Heat-Affected Zones of a Fe-Cr-Ni-Mo High Strength Steel

doi:10.11900/0412.1961.2017.00331

IMR OpenIR

	Microstructure and Impact Toughness of Welding Heat-Affected Zones of a Fe-Cr-Ni-Mo High Strength Steel
	Wen Mingyue 1,2; Dong Wenchao 1; Pang Huiyong 3; Lu Shanping 1
通讯作者	Lu Shanping(shplu@imr.ac.cn)
	2018-04-01
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	54 期号:4 页码:501-511
摘要	Marine engineering steel is the key material for the construction of major marine infrastructure projects. Due to the harsh environment in the deep sea, the mechanical properties such as strength, low temperature toughness and so on of the marine steel are required to be higher. In this work, the weldability of a Fe-Cr-Ni-Mo high-strength steel was studied, and the microstructure and impact toughness of the steel after welding thermal cycling at different peak temperatures were analyzed. The results show that the average impact toughness of characteristic heat affected zone under different temperatures increases first and then decreases with the increase of peak temperature (T-p). The microstructures of coarse grain heat-affected zone (CGHAZ, T-P=1320 degrees C) and fine grain heat-affected zone (FGHAZ, T-p= 1020 degrees C) are quenched martensite. Because of the coarse grain size, the impact toughness of CGHAZ is poor, which is lower than that of FGHAZ. The microstructure of inter-critical heat-affected zone (ICHAZ, T-p =830 degrees C and T-p =760 degrees C) is composed of quenched martensite and tempered martensite. Due to the randomness of the proportion of the interfaces between the mixed microstructures near the V-notch, the impact energy values of ICHAZ fluctuates greatly. The homogeneous fine grain structure in ICHAZ (T-p= 830 degrees C) has a crack arrest effect during the impact deformation, which makes the characteristic zone have the best impact toughness. Although the grain size in ICHAZ (T-P=760 degrees C) is also fine, the existence of the ultra-fine grain zones (the grain size in which is only 1 similar to 2 mu m) benefits the formation of secondary voids under the impact load. The undissolved M2C and MC precipitations in matrix promote the connecting of secondary voids and then form the secondary cracks. As a result, the impact toughness of the characteristic zone is poor, and becomes the weak region of HAZ.
关键词	Fe-Cr-Ni-Mo high strength steel welding heat affected zone impact toughness microstructure
资助者	National Key Research and Development Program of China ; Key Programs of Chinese Academy of Sciences
DOI	10.11900/0412.1961.2017.00331
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2016YFB0300601] ; Key Programs of Chinese Academy of Sciences[GFZD-125-15-003-1]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000433006500003
出版者	SCIENCE PRESS
引用统计	被引频次：4[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/321006/128519
专题	中国科学院金属研究所
通讯作者	Lu Shanping
作者单位	1.Chinese Acad Sci, Inst Met Res, Key Lab Nucl Mat & Safety Assessment, Shenyang 110016, Liaoning, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Liaoning, Peoples R China 3.Wuyang Iron & Steel Co Ltd, Pingdingshan 462500, Peoples R China
推荐引用方式 GB/T 7714	Wen Mingyue,Dong Wenchao,Pang Huiyong,et al. Microstructure and Impact Toughness of Welding Heat-Affected Zones of a Fe-Cr-Ni-Mo High Strength Steel[J]. ACTA METALLURGICA SINICA,2018,54(4):501-511.
APA	Wen Mingyue,Dong Wenchao,Pang Huiyong,&Lu Shanping.(2018).Microstructure and Impact Toughness of Welding Heat-Affected Zones of a Fe-Cr-Ni-Mo High Strength Steel.ACTA METALLURGICA SINICA,54(4),501-511.
MLA	Wen Mingyue,et al."Microstructure and Impact Toughness of Welding Heat-Affected Zones of a Fe-Cr-Ni-Mo High Strength Steel".ACTA METALLURGICA SINICA 54.4(2018):501-511.