借助金相显微镜、SEM、XRD、EDS对凝固过程中的30 mm×150 mm过共晶高铬铸铁试样通以电流强度为2000 A、频率为20 Hz的脉冲电流,对碳化物的形态、尺寸和种类进行分析研究。结果表明,脉冲电流作用下,高铬铸铁中碳化物尺寸显著减小,一部分杆状初生碳化物完全分解小片状,一部分初生碳化物局部溶解成2～3μm细小球状和絮状碳化物。剩余液相共晶反应获得的共晶团较常规铸态时的更加细密。脉冲电流作用下铸铁中碳化物不再为单一的M7C3型,同时出现了MC型、M7C0.45型、M23C6型等新类型的碳化物。
The hypereutectic high chromium cast iron sample（30 mm×150 mm）was treated by electric current pulse（ECP） with 2000 A and 20 Hz during solidification.The shape,size and type of carbides in the sample were researched by means of optical microscopy,SEM,XRD and EDS.The results indicate that the carbides are refined obviously by electric current pulse processing.Some of the rod-like primary carbides are completely decomposed into small pieces.The other primary carbides are transformed to 2-3 μm spheric carbides and flocculent carbides.The eutectic structure is also refined by the effect of ECP.Besides M7C3 carbides,some new type of carbides such as MC,M7C0.45,M23C6 are also found in the treated high chromium cast iron by ECP.
参考文献
| [1] | Tabrett C P;Sare I R .The effect of heat treatment on the abrasion resistance of alloy white irons[J].Wear,1997,203-204:206-219. |
| [2] | Liu HN.;Nomura M.;Ogi K.;Sakamoto M. .Abrasion resistance of high Cr cast irons at an elevated temperature[J].Wear: an International Journal on the Science and Technology of Friction, Lubrication and Wear,2001(1):71-75. |
| [3] | Kibble K A;Pearce J T H .Influence of heat treatment on the microstructure and hardness of 19% Cr high Cr cast iron[J].Cast Metals,1993,6(03):9-15. |
| [4] | J T H Pearce .High Chromium Cast Irons to Resist Abrasive Wear[J].Foundryman,2002(4):156-166. |
| [5] | Durman R W .Progress in abrasion-resistant materials for use in comminution processes[J].International Journal of Mineral Processing,1988,22(1-4):381-399. |
| [6] | R. J. Llewellyn;S. K. Yick;K. F. Dolman .Scouring erosion resistance of metallic materials used in slurry pump service[J].Wear: an International Journal on the Science and Technology of Friction, Lubrication and Wear,2004(6):592-599. |
| [7] | Wiengmoon A;Chalrnangsri T;Brown A et al.Microstructural and erystallographical study of carbides in 30 wt% Cr cast irons[J].Acta Materialia,2005,53(15):4143-4154. |
| [8] | C. P. Tabrett;I. R. Sare;M. R. Ghomashchi .Microstructure-property relationships in high chromium white iron alloys[J].International Materials Reviews,1996(2):59-82. |
| [9] | Atamert S;Bhadeshia H K D H .Microstrncture and stability of Fe-Cr-C hardfacing alloys[J].Materials Science and Engineering,1990,130(01):101-111. |
| [10] | Atamert S;Bhadeshia H K D H.Proceedings of Heat Treatment 1987[M].London:The Institute of Metals,1988:39. |
| [11] | Xiaojun Wu;Jiandong Xing;Hanguang Fu;Xiaohui Zhi .Effect of titanium on the morphology of primary M_7C_3 carbides in hypereutectic high chromium white iron[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1/2):180-185. |
| [12] | 刘政军,程江波,苏允海,刘铎,李永奎.电磁搅拌对堆焊层硬质相形态及性能的影响[J].热加工工艺,2005(04):53-55. |
| [13] | 何树先,王俊,孙宝德,周尧和.高密度脉冲电流对过共晶Al-Si合金凝固组织的影响[J].中国有色金属学报,2002(02):275-278. |
| [14] | Li Q C;Li R X;Yue X D et al.Effect of elcctropulsing on the formation of graphite during solid-state graphitization of spherical graphite iron[J].Materials Chemistry and Physics,2008,112(02):402-406. |
| [15] | Gao M.;He GH.;Yang F.;Guo JD.;Yuan ZX.;Zhou BL. .Effect of electric current pulse on tensile strength and elongation of casting ZA27 alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2002(1/2):110-114. |
| [16] | Xiliang Liao;Qijie Zhai;Jim Luo .Refining mechanism of the electric current pulse on the solidification structure of pure aluminum[J].Acta materialia,2007(9):3103-3109. |
| [17] | 陈琛琚;许光奎;卿上胜.合金高铬铸铁及其应用[M].北京:冶金工业出版社,1999 |
| [18] | Nakada M;Shiohara Y;Flemings M.Modification of solidification structure by pulse electric discharging[J].ISIJ International,1990(30):27. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%