Abstract
This study details the microstructural evolution during hot rolling of AZ31 alloy sheet using a pilot-scale rolling mill. The aim is to understand the deformation mechanisms leading to grain refinement under industrial processing conditions and to design and optimize the hot rolling schedule for AZ31 in order to produce sheet with a fine and homogeneous microstructure. The study examined three different hot rolling temperatures, 350, 400, and 450°C, and two rolling speeds, 20 and 50 rpm. A total thickness reduction of 67% was obtained using multiple passes, with reductions of either 15% or 30% per pass. It was found that the microstructure of the AZ31 alloy was sensitive to the rolling temperature, the reduction (i.e., strain) per pass and the rolling speed (i.e., strain rate). The results show that the large cast grain structure is broken down by segmentation of the cast grain through localized deformation in twin bands, where dynamic recrystallization occurs in these bands as well as at the grain boundaries (necklacing).
Similar content being viewed by others
References
E.F. Emley, Principles of Magnesium Technology (London: Pergamon Press, 1966).
C.S. Roberts, Magnesium and Its Alloys (New York: John Wiley & Sons, 1960).
“Selection and Application of Magnesium and Magnesium Alloys,” Metals Handbook, 10th Edition, 2 (Materials Park, OH: ASM International, 1990), pp. 455–479.
M.M. Avedesian and H. Baker, editors, Magnesium and Magnesium Alloy—ASM Specialty Handbook (Materials Park, OH: ASM International, 1999), pp. 98–102.
J.A. Chapman and D.V. Wilson, J. Inst. Metals, 91 (1962), pp. 39–40.
J. Enss et al., “Properties and Perspectives of Magnesium Rolled Products,” Magnesium Alloys and Their Applications, ed. K.U. Kainer (Weinheim, Germany: Wiley-VCH, 2000).
P. Krajewski, “Elevated Temperature Forming of Sheet Magnesium Alloys,” SAE Paper No. 2001-01-3104 (Warrendale, PA: SAE, 2001).
K. Siegert and S. Jaeger, “Pneumatic Bulging of Magnesium AZ31 Sheet Metal at Elevated Temperatures,” Magnesium Technology 2004, ed. Alan Luo (Warrendale, PA: TMS, 2004), pp. 87–90.
Theory and Modeling Guide, Volume 1, Report ARD 01-7 (ADINA R&D Inc., Watertown, NY, 2001).
E. Essadiqi et al., “Hot Rolling of AZ31 Magnesium Alloy to Sheet Gauge” SAE, 2006-01-0295 (Warrendale, PA: SAE, 2001).
Hiroshi Utsunomiya et al., “High-Speed Heavy Rolling of Magnesium Alloy Sheets,” Magnesium Technology 2006, ed. A.A Luo, N. Neelameggham, and N.R. Beals (Warrendale, PA: TMS, 2006), pp. 201–204.
M.T. Shehata et al., “Microstructure Evolution During Hot-Rolling of AZ31 Mg Alloy,” Magnesium Technology 2006, ed. A.A Luo, N. Neelameggham, and N.R. Beals (Warrendale, PA: TMS, 2006), pp. 225–232.
D. Pantuso, Klaus-Jürgen Bathe, and P.A. Bouzinov, “A Finite Element Procedure for the Analysis of Thermal-Mechanical Solids in Contact,” Computers and Structures, 75 (2000), pp. 551–573.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Essadiqi, E., Shehata, M.T., Javaid, A. et al. Microstructure and temperature monitoring during the hot rolling of AZ31. JOM 61, 25–28 (2009). https://doi.org/10.1007/s11837-009-0117-4
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11837-009-0117-4