The edge quality of AZ31 sheets prepared by online heating rolling (O-LHR) technique under different rolling temperatures has been investigated. The AZ31 sheets are rolled from 3 mm to around 1 mm via four passes under three different temperatures. Each pass reduction keeps a constant about 25%. For comparison, a series of sheets are also rolled by conventional rolling (CR) under the same condition. The macroscopic observation for sheets rolled by both processes and microstructure examination for the rolled sheets via O-LHR are performed to characterize the edge cracking behavior. The results reveal that the edge quality of sheets after O-LHR is better than that through CR and remarkably improves with the increase in temperature. No obvious edge crack appears in AZ31 sheet rolled by O-LHR at a rolling temperature of 250 °C. This can be attributed to the enhanced dynamic recrystallization and the activation of non-basal slip, which results in a homogeneous microstructure at the edge.

研究了在线加热轧制（O-LHR）技术在不同轧制温度下制备的AZ31板材的边缘质量。在三种不同的温度下经过四道次轧制，将AZ31板材从3毫米轧制到1毫米左右。每次通过的减少保持恒定约25％。为了比较，在相同条件下也通过常规轧制（CR）轧制一系列片材。对通过工艺轧制的板材进行宏观观察，并通过O-LHR对轧制板材进行显微组织检查，以表征边缘开裂行为。结果表明，O-LHR处理后的纸张边缘质量优于CR处理，并且随着温度的升高而显着改善。O-LHR在250°C的轧制温度下轧制的AZ31板材没有明显的边缘裂纹。