Microstructure and Mechanical Properties of Welded Joint of a Fe-Cr-Ni-Mo Steel with High-Strength and High-Toughness

doi:10.11900/0412.1961.2017.00236

IMR OpenIR

	Microstructure and Mechanical Properties of Welded Joint of a Fe-Cr-Ni-Mo Steel with High-Strength and High-Toughness
	Hu Xiaofeng; Jiang Haichang; Zhao Mingjiu; Yan Desheng; Lu Shanping; Rong Lijian
通讯作者	Hu Xiaofeng(xfhu@imr.ac.cn)
	2018-01-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	54 期号:1 页码:1-10
摘要	High-strength steel has the advantages of high strength, low cost and good hot and cold workability, etc., which is widely used in various fields of national economy as engineering steel, such as bridge, vehicle, ship, pressure vessel and so on. As increasing strength, the plasticity and toughness of high strength steel have not meet the demand in some industrial areas, especially the low temperature impact toughness. Recently, a Fe-Cr-Ni-Mo steel with high-strength and high-toughness has been developed and has been successfully used to prepare high pressure vessels. In this work, metal active gas (MAG) welding with multi-pass welding was used to join a Fe-Cr-Ni-Mo high-strength and high-toughness steel. The microstructure and fracture morphologies of welded joint are investigated by SEM, EPMA and TEM and the micro-hardness, tensile strength and Charpy impact energy are tested as well. The results show that the morphologies of welded metal (WM) consist of columnar crystal (CC) and equiaxed crystal (EC), where the upper WM is predominantly CC and the proportion of EC increases in the lower WM. The microstructure of upper WM is tempered martensite for the faster cooling rate. Because the higher content of alloying elements in lower WM improves the hardening tendencies, the lower WM is granular bainite. The heat affected zone near WM is coarsen martensite and has the highest hardness (621 HV), which is significantly higher than that of the base metal (BM) (410 HV). The hardness of the upper WM is 365 HV, which is lower than that of BM and the lower WM has higher hardness (450 HV). Therefore, the upper tensile sample of welded joint was broken in the WM and the fracture strength is 1109 MPa and lower than that of BM (1190 MPa). While the fracture position of lower tensile sample is in the BM and the strength is about 1183 MPa. The welded joint of experimental Fe-Cr-Ni-Mo steel has higher strength and the welding factor is not lower than 0.93. Moreover, the impact energy of WM is 53 J.
关键词	Fe-Cr-Ni-Mo high-strength and high toughness steel welded joint tempered martensite granular bainite mechanical property
资助者	National Key Research and Development Program of China
DOI	10.11900/0412.1961.2017.00236
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2016YFB0300601] ; National Key Research and Development Program of China[2016YFB1200501]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000418584100001
出版者	SCIENCE PRESS
引用统计	被引频次：3[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/321006/127180
专题	中国科学院金属研究所
通讯作者	Hu Xiaofeng
作者单位	Chinese Acad Sci, Key Lab Nucl Mat & Safety Assessment, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Hu Xiaofeng,Jiang Haichang,Zhao Mingjiu,et al. Microstructure and Mechanical Properties of Welded Joint of a Fe-Cr-Ni-Mo Steel with High-Strength and High-Toughness[J]. ACTA METALLURGICA SINICA,2018,54(1):1-10.
APA	Hu Xiaofeng,Jiang Haichang,Zhao Mingjiu,Yan Desheng,Lu Shanping,&Rong Lijian.(2018).Microstructure and Mechanical Properties of Welded Joint of a Fe-Cr-Ni-Mo Steel with High-Strength and High-Toughness.ACTA METALLURGICA SINICA,54(1),1-10.
MLA	Hu Xiaofeng,et al."Microstructure and Mechanical Properties of Welded Joint of a Fe-Cr-Ni-Mo Steel with High-Strength and High-Toughness".ACTA METALLURGICA SINICA 54.1(2018):1-10.