镁合金热辊轧制温升效应研究

Study on the temperature rise effect of AZ31B Mg alloy during rolling with heated rolls

摘要:

本研究在之前冷辊轧制温升研究的基础上,进一步研究了AZ31B镁合金不同工艺条件下热辊轧制厚度方向温度分布及其与组织的关系,并在此基础上建立了能量守恒的简化方程来预测温升。结果表明：变形过程中温升都与压下量正相关,而与初轧温度反相关。辊温显著影响轧制时的表面温降和总体温升,使得热辊轧制表层组织中孪晶明显减小,轧板中再结晶更加充分。此外,基于能量守恒的简化方程的计算结果与实测数据吻合较好。

Abstract:

The temperature distribution along the thickness direction of AZ3lB Mg alloy was measured during rolling with heated rolls, basing on the previous study of temperature rise effect during rolling with cold (RT) rolls. The effect of different rolling conditions on temperature distribution and its relation with microstructure were investigated. On this basis, simplified energy-based state equations were established to predict temperature rises. The results show the temperature rises during rolling both increased with either increased reduction or decreased initial rolling temperature. The roll temperature had obvious effects on surface temperature and overall temperature rise. As a result, the amount of twin in surface layer decreased sharply and the overall recrystallization zone increased during rolling with heated roll. The calculated results by energy-based state equations were in good agreement with experimental ones.