EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL

doi:10.11900/0412.1961.2015.00532

CORC > 金属研究所 > 中国科学院金属研究所

	EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL
	Guo Wenying 1,2; Hu Xiaoqiang 2; Ma Xiaoping 2; Li Dainzhong 2
刊名	ACTA METALLURGICA SINICA
	2016-07-01
卷号	52 期号:7 页码:769-777
关键词	wear-resistant steel TiN precipitate solidification microstructure secondary dendrite arm spacing
ISSN号	0412-1961
DOI	10.11900/0412.1961.2015.00532
通讯作者	Hu Xiaoqiang(xqhu@imr.ac.cn)
英文摘要	As an important type of wear-resistant material, the low-alloyed medium carbon wear resistant steel has been widely used in mining, power and metallurgical industries due to its low cost and excellent mechanical properties. However, the coarse as-cast microstructure tends to form in large wear resistant castings because of the long solidification time. As a result, spalling wear resulting from the preferential initiation and propagation of cracks along interdendrite will occur during service process, which severely degrades the wear resistance and service life. In this work, Ti is added to improve the mechanical properties of medium carbon Cr-Mo wear resistant steel. The precipitation behavior of TiN in the solidification process and its effect on the solidification microstructure were investigated by thermodynamic calculation, constant temperature solidification experiment at solid-liquid two phase region and continuous cooling solidification experiment by using OM, SEM, EDS and EPMA. The results show that TiN precipitation temperature gradually increases at solid-liquid two-phase region with the increase of contents of Ti and N. TiN precipitates directly in the liquid region when Ti and N contents (mass fraction) are 0.090% and 0.014%, respectively. Holding at different temperatures of solid-liquid two-phase region, a very small amount of TiN precipitates are present within the dendritic arm, and a large number of TiN precipitates are present at the interdendritic positions and frontiers of dendrites. After quenching, in the remaining liquid most of TiN are present at the boundaries of equiaxed grain and a little amount of TiN stay within the equiaxed grain. During the continuous cooling solidification, TiN precipitation temperature is the main factor affecting the refinement of solidification microstructure. With the increase of Ti content, TiN precipitation temperature increases. At the same time, the actual solidification temperature of liquid steel rises, the solidification temperature range broadens and the local solidification time extends, which results in the increase of secondary dendrite arm spacing. When Ti content exceeds 0.066%, TiN precipitation temperature is near or above the liquidus line. The actual solidification temperature of liquid steel remains unchanged. Therefore, the secondary dendrite arm spacing becomes stable.
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000385747800001
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/123025]
专题	金属研究所_中国科学院金属研究所
通讯作者	Hu Xiaoqiang
作者单位	1.Univ Sci & Technol China, Sch Chem & Mat Sci, Hefei 230022, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Guo Wenying,Hu Xiaoqiang,Ma Xiaoping,et al. EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL[J]. ACTA METALLURGICA SINICA,2016,52(7):769-777.
APA	Guo Wenying,Hu Xiaoqiang,Ma Xiaoping,&Li Dainzhong.(2016).EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL.ACTA METALLURGICA SINICA,52(7),769-777.
MLA	Guo Wenying,et al."EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL".ACTA METALLURGICA SINICA 52.7(2016):769-777.