Abstract
The microstructure and mechanical properties of high boron white cast irons with about 4 wt% chromium before and after treating with rare earth magnesium alloy were studied in this article. The experimental results indicate that the cast irons comprise a dendritic matrix and interdendritic eutectic borides M2B and M′0.9Cr1.1B0.9 that distributed in the form of continuous network in as-cast condition. The matrix is made up of fine pearlite in the alloys with and without modification, but the grain size of the matrix is decreased greatly after modification. After water quenching at 1,303 K and tempering at 473 K, the matrix of the alloy mostly changes to lath-type martensite. For the alloy without modification the boride morphology remains almost unchanged after heat treatment. And a secondary precipitation of M23(C,B)6 compound appears in the central region of dentritic matrix grains. The morphology of the eutectic borides is changed to the form of isolated blocks after heat treatment and there is only little intragranular M23(B,C)6 particles in the matrix are found in the alloy modified with rare earth magnesium alloy. The modification by rare earth magnesium alloy can refine the primary austenite and the eutectic borides. Combined with a high austenitizing temperature the modification can improve the morphology of the borides which results in the improvement of toughness and tensile strength.
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References
Niu LB, Hojamberdiev M, Xu YH, Wu H (2010) J Mater Sci 45:4532. doi:10.1007/s10853-010-4549-6
Kumari UR, Rao PP (2009) J Mater Sci 44:1082. doi:10.1007/s10853-008-3195-8
Erdogan M, Kilicli V, Demir B (2009) J Mater Sci 44:1394. doi:10.1007/s10853-006-1415-7
Li Y, Liu Z, Chen X (2008) Int J Cast Met Res 21:67
Liu Z, Chen X, Li X (2008) Metall Mater Trans A39:636
Baker H (1990) ASM handbook. Alloy phase diagram. ASM International, Inc., Materials Park
Smith WF (1996) Principles of materials science and engineering. McGraw-Hill, New York
Egorov MD, Sapozhnikov Yu L, Shakhnazarov Yu V (1989) Metal Sci Heat Treat 31:387
Gol’dshtein Ya E, Mizin VG (1988) Metal Sci Heat Treat 30:479
The first works of Benxi Steel Corp. (1977) Boron Steel. Metallurgical Industry Press, Beijing
Guo CQ (2002) Improving the ductility and toughness of Fe–Cr–B cast irons. The University of Queensland, Brisbane
Nevar NF, Belskii EI (1990) SU 1,581,771
Lakeland KD (2001) US 6,171,222 B1
Lakeland KD (2004) US 6,689,312 B2
Liu Z, Li Y, Chen X, Hu K (2008) Mater Sci Eng A486:112
Liu Z, Chen X, Li Y, Hu K (2009) J Iron Steel Res Int 16:37
Liu Z (2007) Research on high boron white cast iron. Tsinghua University, Beijing
Li H, Mclean A, Rure JW, Sommerville ID (1998) Metall Mater Trans B19:383
Ge HL, Youdelis WV, Chen GL (1989) J Mater Sci Technol 5:1207
Lan J, He JJ, Ding WJ, Wang QD, Zhu YP (2001) J Rear Earths 19:280
Chen X, Li Y (2006) Trans Mater Heat Treat 27:73
Chen X, Li Y (2007) Mater Sci Eng A444:298
Lin D, Zhang Y (1998) Mater Sci Eng A256:39
Jahazi M, Jonas JJ (2002) Mater Sci Eng A335:49
He X, Chu Y, Ke J (1982) Acta Metall Sin 18:11
Chu Y, He X, Li T, Xu T, Ke J (1987) Acta Metall Sin 23:A169
Hillert M, Sundman B (1976) Acta Metall 24:731
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The authors acknowledge financial support from the National Natural Science Foundation of China (No. 50974080).
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Chen, X., Li, Y. & Zhang, H. Microstructure and mechanical properties of high boron white cast iron with about 4 wt% chromium. J Mater Sci 46, 957–963 (2011). https://doi.org/10.1007/s10853-010-4840-6
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DOI: https://doi.org/10.1007/s10853-010-4840-6