Heat-transfer analysis of AZ31B Mg alloys during single-pass flat rolling: Experimental verification and mathematical modeling

摘要

The present study aimed to investigate the temperature distribution in AZ31B Mg alloy plate along the thickness direction during the single-pass flat rolling. The detection and tracking of the plate temperature were carried out under different rolling conditions. Due to the influence of the complex heat transfer factors during rolling, the uneven degree of the temperature distribution was different, which was also reflected in microstructure characteristics between different metal layers. The temperature and microstructure both exhibited great similarity between the center and 1/4.H in the rolling due to the main effect of heat generation due to plastic work, while drastic difference between the surface and the center and 1/4.H due to the surface chilling effect. The maximum surface-temperature drop and center-temperature rise through rolling, regarded as the rolling exit temperature-distribution status, both presented mathematical relationships with respect to rolling process parameters. During the modeling process of the maximum surface-temperature drop, the proportion coefficient of chilling layer was identified for AZ31B Mg alloys, and it depends on the work roll temperature. In addition, during the modeling process of the maximum center-temperature rise, the theoretical equation of temperature rise due to plastic deformation could be reasonably simplified for AZ31B Mg alloys. (C) 2017 Elsevier Ltd. All rights reserved.