Abstract:

The influence of rolling reduction ratio and rolling temperature on the instantaneous temperature rise in the central layer （∆t₁）， the steady-state temperature rise after rolling （∆t₂）， and the instantaneous temperature drop in the surface layer （∆t₃） of AZ31B magnesium alloy during the rolling process was investigated. The near-isothermal rolling state of the rolled slab was evaluated based on the measured rolling temperature data of AZ31B sheets， and the corresponding empirical formulas were established. The results show that ∆t₁ and ∆t₂ gradually increase with rolling reduction ratio increases， while ∆t₃ first increases and then decreases， and the changes in ∆t₁ and ∆t₂ show a linear relationship with the increase in rolling reduction ratio. In addition， as rolling temperature rises， ∆t₁ and ∆t₂ gradually decrease， and ∆t₃ gradually increases. Moreover， the slope of the linear relationship curve between ∆t₁， ∆t₂， and the rolling reduction ratio gradually decreases. The trend of the prediction curve obtained from the empirical formula is in good agreement with the experimental data， confirming the feasibility of near-isothermal rolling for AZ31B magnesium alloy.

Key words: AZ31B magnesium alloy, near-isothermal rolling, rolling temperature, rolling reduction ratio, thermal deformation