Abstract
Near-net shape manufacturing (NNSM) of thin steel sections by spray casting eliminates casting as a separate step with attendant improved microstructures and properties and significant energy savings. The process involves atomization of a stream of liquid metal and deposition of droplets in the generated spray on a moving substrate at mass flow rates of 0.25 to 2.5 kg/s. In this paper, NNSM of steel strip by the Osprey spray casting process is investigated by combining numerical simulation and experiments. Critical input parameters for the computation are quantified utilizing existing state-of-the-art mathematical models and specific experiments. Numerical computation of the consolidation of the spray at the substrate during manufacture of thin sections is conducted using bothcontinuum anddiscrete event (“splat solidification”) approaches to predict: (1) variation of strip thickness in the transverse dimension and (2) isotherms and cooling rates across the strip thickness. Predicted geometries of the strip simulated by the continuum model are in good agreement with measurements. Predicted isotherms in narrow strip by the continuum approach are in reasonable agreement with thermocouple measurements for intermediate thicknesses (2 to 5 mm), and the observed microstructure is consistent with predicted cooling rates. The discrete event model predicts significantly higher cooling rates than the continuum model in the basal portion of the strip. This is consistent with the observed grain size in thin strip (<l-mm thick) and in the basal portion of thick strip. Beyond a threshold thickness, however, the discrete event model confirms the formation and persistence of a partially liquid layer at the growing surface of the deposit with an attendant decrease in the cooling rate. The influence of critical parameters on “splat solidification” is analyzed and assessed.
Similar content being viewed by others
References
W.A. Tony:Iron and Steelmaker, 1987, vol. 14 (12), pp. 11–13.
P.C. Mathur: M.S. Thesis, Drexel University, Philadelphia, PA, 1986.
P.C. Mathur, D. Apelian, and A. Lawley:Acta Metall., 1989, vol. 37 (1), pp. 429–43.
P.C. Mathur: Ph.D. Thesis, Drexel University, Philadelphia, PA, 1988.
A.R.E. Singer and R.W. Evans:Met. Technol., 1983, vol. 10, pp. 61–68.
E. Gutierrez-Miravete, E.J. Lavernia, G.M. Trapaga, J. Szekely, and N.J. Grant:Metall. Trans. A, 1989, vol. 20A (1), pp. 71–85.
H. Jones:Rapid Solidification of Metals and Alloys, The Institution of Metallurgists, London, 1982, p. 43.
E. Gutierrez-Miravete, G.M. Trapaga, and J. Szekely:Casting of Near Net Shape Products, Y. Sahai, J.E. Battles, R.S. Carbonara, and C.E. Mobley, eds., TMS, Warrendale, PA, 1988, pp. 133–51.
A.G. Gillen, P.C. Mathur, D. Apelian, and A. Lawley:Prog. Powder Metall., E.A. Carlson and G. Gaines, eds., Metal Powder Industries Federation, Princeton, NJ, 1986, vol. 42, pp. 753–73.
P.C. Mathur and D. Apelian: in Book Series on Powder Metallurgy, I. Jenkins and J.V. Wood, eds., Institute of Metals, London, vol. 3, in press.
P.C. Mathur, S. Annavarapu, D. Apelian, and A. Lawley:J. Miner. Met. Mater. Soc., 1989, vol. 41 (10), pp. 23–28.
B.P. Bewlay and B. Cantor: inRapidly Solidified Materials, P.W. Lee and R.S. Carbonara, eds., ASM, Metals Park, OH, 1986, p. 97. 13. P.S. Grant, S. Rogers, B. Cantor, and L. Katgerman: Presented at the TMS Annual Meeting, Anaheim, CA, Feb. 18–22, 1990.
M.C. Flemings:Solidification Processing, McGraw-Hill, New York, NY, 1974.
J. Madjeski:Int. J. Heat Mass Transfer, 1976, vol. 19, pp. 1009–13.
E.R. Garrity: Ph.D. Thesis, Drexel University, Philadelphia, PA, 1989.
R.M. German:Powder Metallurgy Science, Metal Powder Industries Federation, Princeton, NJ, 1984, pp. 32–33.
P. Mathur, Y.C. Wei, and D. Apelian: inModeling of Control of Welding and Casting Processes IV, A.F. Giamei and G.J. Abbaschian, eds., TMS, Warrendale, PA, 1988, p. 275.
H.S. Carslaw and J.C. Jaeger:Conduction of Heat in Solids, Oxford University Press, Oxford, United Kingdom, 1973, pp. 75–76.
H. Martin: inAdvances in Heat Transfer, J.P. Harnett and T.F. Irvine, eds., Academic Press, New York, NY, 1977, vol. 13.
A. Lawley and D. Apelian: Drexel University Tech. Rep. No. 2, NSF Grant No. MSM-8519047, 1988.
S. Annavarapu: M.S. Thesis, Drexel University, Philadelphia, PA, 1987.
S. Annavarapu, A. Lawley, and D. Apelian:Metall. Trans. A, 1988, vol. 19A (12), pp. 3077–86.
A. Suzuki, T. Suzuki, Y. Nagaoka, and Y. Iwata:J. Jpn. Inst. Met., 1968, vol. 32, p. 1301.
N.J. Grant: inCasting of Near Net Shape Products, Y. Sahai, J. Battles, R.S. Carbonara, and C.E. Mobley, eds., TMS, Warrendale, PA, 1988, p. 203.
A.R.E. Singer:J. Inst. Met., 1972, vol. 100, pp. 185–90.
A.G. Leatham, W. Reichelt, and O.H. Metelmann: inNear Net Shape Manufacturing Process, P.W. Lee and B.L. Ferguson, eds., ASM INTERNATIONAL, Metals Park, OH, 1988, p. 259.
K. Wunnenberg, R. Flender, W. Fix, and R. Schneider:Proc. Int. Cont. Casting Conf, Brussels, Belgium, May 17, 1988, pp. 728–41.
G. Hartmann, P.N. Hansen, and P.R. Sahm: inModeling and Control of Casting and Welding Processes IV, A.F. Giamei and G.J. Abbaschian, eds., TMS, Warrendale, PA, 1988, pp. 915–21.
Thermophysical Properties of Matter, TPRC Data Series, Purdue University, Plenum Press, New York, NY, 1977.
R.D. Pehlke, A. Jeyarajan, and H. Wada:Summary of Thermal Properties for Casting Alloys and Mold Materials, National Science Foundation, Washington, DC, NSF/MEA-82028, 1982.
Author information
Authors and Affiliations
Additional information
DIRAN APELIAN, formerly Howmet Professor of Materials Engineering at Drexel University
Rights and permissions
About this article
Cite this article
Annavarapu, S., Apelian, D. & Lawley, A. Spray casting of steel strip: Process analysis. Metall Trans A 21, 3237–3256 (1990). https://doi.org/10.1007/BF02647318
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02647318