Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment

IMR OpenIR

	Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment
其他题名	Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment
	Gao Minqiang; Qu Yingdong; Li Guanglong; You Junhua; Li Rongde
	2017
发表期刊	JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
ISSN	1006-706X
卷号	24 期号:8 页码:838-843
摘要	Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment was investigated. Fractographies and microstructures of heat treated samples were observed using a scanning electron microscope and mechanical properties were measured by a universal tensile test machine. The results indicated that during isothermal annealing at 750 degrees C, the tensile strength of pearlitic ductile cast iron was increased to a peak value at 0. 5 h, and decreased gradually thereafter but the elongation was enhanced with the increase of annealing time. Moreover, the diffusion coefficient of carbon atoms could he approximately calculated as 0. 56 mu m(2)/s that could he regarded as the short-range diffusion. As the holding time was short (0. 5 h), diffusion of carbon atoms was incomplete and mainly occurred around the graphites where the morphology of cementites changed from fragmentized shape to granular shape. In addition, the ductile cast iron with tensile strength of 740 MPa and elongation of 7% could he achieved after graphitization annealing heat treatment for 0. 5 h. Two principal factors should he taken into account. First, the decomposition of a small amount of cementites was beneficial for increasing the ductility up to elongation of 7%. Second, the diffusion of carbon atoms from cementites to graphites could improve the binding force between graphites and matrix, enhancing the tensile strength to 740 MPa.
其他摘要	Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment was investigated.Fractographies and microstructures of heat treated samples were observed using a scanning electron microscope and mechanical properties were measured by a universal tensile test machine. The results indicated that during isothermal annealing at 750°C,the tensile strength of pearlitic ductile cast iron was increased to a peak value at 0.5h,and decreased gradually thereafter but the elongation was enhanced with the increase of annealing time.Moreover,the diffusion coefficient of carbon atoms could be approximately calculated as 0.56μm2/s that could be regarded as the shortrange diffusion.As the holding time was short(0.5h),diffusion of carbon atoms was incomplete and mainly occurred around the graphites where the morphology of cementites changed from fragmentized shape to granular shape.In addition,the ductile cast iron with tensile strength of 740MPa and elongation of 7%could be achieved after graphitization annealing heat treatment for 0.5h.Two principal factors should be taken into account.First,the decomposition of a small amount of cementites was beneficial for increasing the ductility up to elongation of 7%.Second,the diffusion of carbon atoms from cementites to graphites could improve the binding force between graphites and matrix,enhancing the tensile strength to 740MPa.
关键词	MECHANICAL-PROPERTIES GRAPHITE MICROSTRUCTURE Pearlitic ductile cast iron Cementite decomposition Diffusion Carbon atom Graphitization annealing heat treatment
收录类别	CSCD
语种	英语
资助项目	[Program for Innovative Research Team in University of Liaoning Province] ; [National Natural Science Foundation of China]
CSCD记录号	CSCD:6063472
引用统计	被引频次：2[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/148579
专题	中国科学院金属研究所
作者单位	中国科学院金属研究所
推荐引用方式 GB/T 7714	Gao Minqiang,Qu Yingdong,Li Guanglong,et al. Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment[J]. JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL,2017,24(8):838-843.
APA	Gao Minqiang,Qu Yingdong,Li Guanglong,You Junhua,&Li Rongde.(2017).Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment.JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL,24(8),838-843.
MLA	Gao Minqiang,et al."Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment".JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL 24.8(2017):838-843.