| Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment | |
| Alternative Title | Cementites decomposition of a pearlitic ductile cast iron during graphitization annealing heat treatment |
| Gao Minqiang; Qu Yingdong; Li Guanglong; You Junhua; Li Rongde | |
| 2017 | |
| Source Publication | JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
 |
| ISSN | 1006-706X |
| Volume | 24Issue:8Pages:838-843 |
| Abstract | 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. |
| Other Abstract | 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. |
| Keyword | MECHANICAL-PROPERTIES GRAPHITE MICROSTRUCTURE Pearlitic ductile cast iron Cementite decomposition Diffusion Carbon atom Graphitization annealing heat treatment |
| Indexed By | CSCD |
| Language | 英语 |
| Funding Project | [Program for Innovative Research Team in University of Liaoning Province] ; [National Natural Science Foundation of China] |
| CSCD ID | CSCD:6063472 |
| Citation statistics |
Cited Times:1[CSCD]
[CSCD Record]
|
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/148576 |
| Collection | 中国科学院金属研究所 |
| Affiliation | 中国科学院金属研究所 |
| Recommended Citation 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. |
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