Liquid-solid interface control of BFe10-1-1 cupronickel alloy tubes during HCCM horizontal continuous casting and its effect on the microstructure and properties

Abstract

Based on horizontal continuous casting with a heating-cooling combined mold (HCCM) technology, this article investigated the effects of processing parameters on the liquid-solid interface (LSI) position and the influence of LSI position on the surface quality, microstructure, texture, and mechanical properties of a BFe10-1-1 tube (ϕ50 mm × 5 mm). HCCM efficiently improves the temperature gradient in front of the LSI. Through controlling the LSI position, the radial columnar-grained microstructure that is commonly generated by cooling mold casting can be eliminated, and the axial columnar-grained microstructure can be obtained. Under the condition of 1250°C melting and holding temperature, 1200–1250°C mold heating temperature, 50–80 mm/min mean drawing speed, and 500–700 L/h cooling water flow rate, the LSI position is located at the middle of the transition zone or near the entrance of the cooling section, and the as-cast tube not only has a strong axial columnar-grained microstructure $(\{ hkl\} < 6\bar 21 > , \{ hkl\} < 2\bar 21 > )$ due to strong axial heating conduction during solidification but also has smooth internal and external surfaces without cracks, scratches, and other macroscopic defects due to short solidified shell length and short contact length between the tube and the mold at high temperature. The elongation and tensile strength of the tube are 46.0%–47.2% and 210–221 MPa, respectively, which can be directly used for the subsequent cold-large-strain processing.

Keywords

copper-nickel alloys / tubes / continuous casting / interfaces / textures / mechanical properties

References

[1] Glover TJ. Copper-nickel alloy for the construction of ship and boat hulls. Br. Corros. J., 1982, 17(4): 155.

[2] Yan ZM, Li XT, Qi K. Study on horizontal electromagnetic continuous casting of CuNi10Fe1Mn alloy hollow billets. Mater. Des., 2009, 30(6): 2072.

[3] Gan CL, Liu XF, Huang HY, Xie JX. Fabrication process, microstructure and mechanical properties of BFe10-1-1 alloy tubes by continuous unidirectional solidification. Acta Metall Sin., 2010, 46(12): 1549.

[4] Xie JX, Lou HF, Wang ZD, Hu PX, Zhang H, Dong YZ, Kang JL, Miao GW, Fu XZ, Yan M, Guan BH, Jiang XL. Compact Process for Fabrication of Copper and Copper Alloy Precision Tube, 2009

[5] Ohno A, Motoyasu G, Kawai H. Strengthening and bending deformability of Al-4.5 mass% Mg alloy billets produced by heated mold continuous casting method (OCC). Light Met., 1990, 40(11): 817.

[6] Xie JX, Mei J, Liu XH, Liu XF. A Kind of Process and Equipment for Fabricating Cupronickel Pipes with Heating-Cooling Combined Mold Casting, 2012

[7] Mei J, Liu XH, Xie JX. Microstructure and mechanical properties of BFe10 cupronickel alloy tubes fabricated by a horizontal continuous casting with heatingcooling combined mold technology. Int. J. Miner. Metall. Mater., 2012, 19(4): 339.

[8] Mei J, Liu XH, Xie JX. Solidification temperature field simulation of BFe10 cupronickel tube during heatingcooling combined mold continuous casting. Chin. J. Nonferrous Met., 2012, 22(5): 1430.

[9] Li TL, Gao YF, Bei H, George EP. Indentation Schmid factor and orientation dependence of nanoindentation pop-in behavior of NiAl single crystals. J. Mech. Phys. Solids, 2011, 59(6): 1147.

[10] Kim KH, Koo YM. Glide strains dependency on Schmid’s factor of secondary slip systems in copper single crystals. Mater. Lett., 2002, 57(1): 6.

[11] Godet S, Jiang L, Luo AA, Jonas JJ. Use of Schmid factors to select extension twin variants in extruded magnesium alloy tubes. Scripta Mater., 2006, 55(11): 1055.

[12] Gao KW, Liu MY, Zou FL, Pang XL, Xie JX. Characterization of microstructure evolution after severe plastic deformation of pure copper with continuous columnar crystals. Mater. Sci. Eng. A, 2010, 527(18–19): 4750.

[13] Fu HD, Zhang ZH, Yang Q, Xie JX. Strainsoftening behavior of an Fe-6.5wt%Si alloy during warm deformation and its applications. Mater. Sci. Eng. A., 2011, 528(3): 1391.

[14] Wang Y, Huang HY, Xie JX. Texture evolution and flow stress of columnar-grained polycrystalline copper during intense plastic deformation process at room temperature. Mater. Sci. Eng. A, 2011, 530, 418.

[15] Mei J, Liu XH, Xie JX. Evolution of microstructure, texture and mechanical properties of BFe10-1-1 tube with microstructure along axial orientation during cold-rolling. Chin. J. Nonferrous Met., 2012, 22(9): 2529.