EFFECTS OF HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF WELD METAL WITH Nb ADDITION

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	EFFECTS OF HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF WELD METAL WITH Nb ADDITION
	Wei Shitong 1; Lu Shanping 1; He Guangzhong 2; Zhao Xu 2; Li Dianzhong 1; Li Yiyi 1
通讯作者	Lu Shanping(shplu@imr.ac.cn)
	2009-09-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	45 期号:9 页码:1063-1069
摘要	There is a strong demand within the steel industry to develop high strength microalloyed steels and matching welding materials for satisfying the ever increasing industrial needs. Nb microalloyed steel is one of the important structure materials. The weldability determines the industrial application prospect of Nb microalloyed steel. The majority of previous studies concerning Nb bearing steels have been focus on the transformation behavior of Nb bearing steels in thermomechanical process and the effect of Nb element on the process. However, the research on the matching welding materials for Nb bearing steels and the effects of heat treatment process on the microstructure and mechanical properties of Nb bearing weld metal were seldom reported. In this paper, Nb bearing S355J2G3 steel plates for high-speed train bogie were welded using welding wires with and without Nb addition. Differences of properties at the different regions in the as-welded joint, and the effects of the Nb element and the different post weld heat treatments on the microstructure and the mechanical property of the weld metal were analyzed systematically. Experimental results showed that the weld metal toughness is the weakest link of the welding joint properties. Nb addition can improve the strength of the weld metal, but has no obvious effects on the plasticity and impact toughness. After stress relief annealing, the strength of the Nb free weld metal decreased, while the elongation and impact toughness increased. However, for the Nb bearing weld metal, stress relief annealing can improve the strength of the weld metal significantly, but deteriorate the elongation and impact toughness. NbC particles were found in the as-annealing weld metal. With the increase of the normalizing temperature, the microstructure and mechanical property of the Nb free weld metal have no obvious change, while, for the Nb bearing weld metal, the strength increases obviously and the elongation and impact toughness decrease. Therefore, setting the normalizing temperature properly is the key to get higher toughness for the Nb bearing weld metal. It was simultaneously found that the content of widmanstatten ferrite in the Nb bearing weld metal increases obviously with the increase of the normalizing temperature. Furthermore, when the normalizing temperature was set at 920 degrees C, the size of the NbC particles in weld metal is larger than that in the as-annealed weld metal. However, when the normalizing temperature was raised to 1200 degrees C, the NbC particles will disappear because of its dissolution at higher temperature.
关键词	Nb microalloyed steel heat treatment process weld metal addition of Nb microstructure mechanical property
收录类别	SCI
语种	英语
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000271663400007
出版者	SCIENCE PRESS
引用统计	被引频次：2[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/321006/97889
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, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 2.Changchun Railway Vehicles Co Ltd, Changchun 130062, Peoples R China
推荐引用方式 GB/T 7714	Wei Shitong,Lu Shanping,He Guangzhong,et al. EFFECTS OF HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF WELD METAL WITH Nb ADDITION[J]. ACTA METALLURGICA SINICA,2009,45(9):1063-1069.
APA	Wei Shitong,Lu Shanping,He Guangzhong,Zhao Xu,Li Dianzhong,&Li Yiyi.(2009).EFFECTS OF HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF WELD METAL WITH Nb ADDITION.ACTA METALLURGICA SINICA,45(9),1063-1069.
MLA	Wei Shitong,et al."EFFECTS OF HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF WELD METAL WITH Nb ADDITION".ACTA METALLURGICA SINICA 45.9(2009):1063-1069.