Effect of arsenic content and quenching temperature on solidification microstructure and arsenic distribution in iron-arsenic alloys

Abstract

The solidification microstructure, grain boundary segregation of soluble arsenic, and characteristics of arsenic-rich phases were systematically investigated in Fe-As alloys with different arsenic contents and quenching temperatures. The results show that the solidification microstructures of Fe-0.5wt%As alloys consist of irregular ferrite, while the solidification microstructures of Fe-4wt%As and Fe-10wt%As alloys present the typical dendritic morphology, which becomes finer with increasing arsenic content and quenching temperature. In Fe-0.5wt%As alloys quenched from 1600 and 1200°C, the grain boundary segregation of arsenic is detected by transmission electron microscopy. In Fe-4wt%As and Fe-10wt%As alloys quenched from 1600 and 1420°C, a fully divorced eutectic morphology is observed, and the eutectic Fe₂As phase distributes discontinuously in the interdendritic regions. In contrast, the eutectic morphology of Fe-10wt%As alloy quenched from 1200°C is fibrous and forms a continuous network structure. Furthermore, the area fraction of the eutectic Fe₂As phase in Fe-4wt%As and Fe-10wt%As alloys increases with increasing arsenic content and decreasing quenching temperature.

Keywords

iron-arsenic alloys / solidification / microstructure / segregation / eutectic

References

[1] Xian AP, Zhang D, Wang YK. Impurities in steel and their influence on steel properties. Iron steel, 1999, 34(10): 64.

[2] Suzuki M, Piccone TJ, Flemings MC, Brody HD. Solidification of highly undercooled Fe–P alloys. Metall. Trans. A, 1991, 22(11): 2761.

[3] Predel B, Frebel M. Precipitation behavior of a-solid solutions of the Fe–Sn system. Metall. Trans., 1973, 4(1): 243.

[4] Liu ZZ, Kuwabara M, Satake R, Nagata T. Effect of Sn on microstructure and sulfide precipitation in ultra low carbon steel. ISIJ Int., 2009, 49(7): 1087.

[5] Yuan Y, Sassa K, Iwai K, Wang Q, He JC, Asai S. Copper distribution in Fe–Cu and Fe–C–Cu alloys under imposition of an intense magnetic field. ISIJ Int., 2008, 48(7): 901.

[6] Chen Z, Liu F, Wang HF, Yang W, Yang GC, Zhou YH. Formation of single-phase supersaturated solid solution upon solidification of highly undercooled Fe–Cu immiscible system. J. Cryst. Growth, 2008, 310(24): 5385.

[7] Kudoh M, Tezuka M, Matsuura K. Effect of niobium on the formation of microstructure and grain boundary in Fe–Nb and Fe–C–Nb alloys. ISIJ Int., 2006, 46(12): 1871.

[8] Yi DW, Xing JD, Ma SQ, Fu HG, Li YF, Chen W, Yan JB, Zhang JJ, Zhang RR. Investigations on microstructures and two-body abrasive wear behavior of Fe–B cast alloy. Tribol. Lett., 2012, 45(3): 427.

[9] Ma SQ, Xing JD, Liu GF, Yi DW, Fu HG, Zhang JJ, Li YF. Effect of chromium concentration on microstructure and properties of Fe–3.5B alloy. Mater. Sci. Eng. A, 2010, 527(26): 6800.

[10] Zhang XZ. Solidification modes and microstructure of Fe–Cr alloys solidified at different undercoolings. Mater. Sci. Eng. A, 1998, 247(1-2): 214.

[11] Subramanian SV, Haworth CW, Kirkwood DH. Development of interdendritic segregation in an iron-arsenic al loy. J. Iron Steel Inst., 1968, 206(11): 1124.

[12] Yin GJ. The distribution of arsenic in steel. Iron steel, 1981, 16(2): 20.

[13] Okamoto H. The As–Fe (arsenic–iron) system. J. Phase Equilib., 1991, 12(4): 457.

[14] Zhou L, Wang N, Zhang L, Yao WJ. The effects of the minority phase on phase separation in Fe–Sn hypermonotectic alloy. J. Alloys Compd., 2013, 555, 88.

[15] Guan XR, Liu EZ, Zheng Z, Yu YS, Tong J, Zhai YC. Solidification behavior and segregation of Re-containing cast Ni-base superalloy with different Cr content. J. Mater. Sci. Technol., 2011, 27(2): 113.

[16] Oi T, Sato K. Autoradiography of Fe–As and Fe–Sn dilute alloys II: grain boundary segregation of the alloying elements. Trans. Jpn. Inst. Met., 1969, 10(1): 39.

[17] Zhu YZ, Li JC, Liang DM, Liu P. Distribution of arsenic on micro-interfaces in a kind of Cr, Nb and Ti microalloyed low carbon steel produced by a compact strip production process. Mater. Chem. Phys., 2011, 130(1-2): 524.

[18] Zhu YZ, Zhu Z, Xu JP. Grain boundary segregation of minor arsenic and nitrogen at elevated temperatures in a microalloyed steel. Int. J. Miner. Metall. Mater., 2012, 19(5): 399.

[19] Dargusch MS, Nave M, McDonald SD, StJohn DH. The effect of aluminium content on the eutectic morphology of high pressure die cast magnesium–aluminium alloys. J. Alloys Compd., 2010, 492(1-2): L64.

[20] Zhu TP, Chen ZW, Gao W. Effect of cooling conditions during casting on fraction of ß-Mg17Al12 in Mg–9Al–1Zn cast alloy. J. Alloys Compd., 2010, 501(2): 291.

[21] Int. J. Miner. Metall. Mater., 2013, 20(9)

[22] St John DH, Dahle AK, Abbott T, Nave MD, Qian M. Solidification of cast magnesium alloys, 2003, San Diego, The 2003 TMS Annual Meeting, 95.