The mechanical behavior of zinc alloys drastically depends on strain rate and temperature, which are not constant during forming processes. During the production of zinc sheets, the slight variations of the industrial equipment parameters induce different local thermomechanical conditions. These variations could be stemming from a non-homogeneous cooling during rolling process, or local segregation of alloys and so on …. The result of these differences entails a significant scattering of material parameters as shown in (Milesi et al. J Mat Process Tech 245:134-148, 2017). This paper tackles the scattering of material parameters through an adapted Norton-Hoff behavior law. Then, four parameters have been identified with a standard Generalized Reduced Gradient method (GRG). Moreover, an exhaustive analysis of the entire rolled coil has been carried out to differentiate the variation coming from the material from the one due to the process. This study also encompasses the influence of strain rate on the forming limit diagram and therefore on the calculation of the forming limit stress diagram.

锌合金的机械性能很大程度上取决于应变率和温度，而应变率和温度在成型过程中并不恒定。在生产锌片期间，工业设备参数的细微变化会引起不同的局部热机械条件。这些变化可能是由于轧制过程中不均匀的冷却，或者是合金的局部偏析等等。这些差异的结果导致材料参数的显着分散，如（Milesi等人，J Mat Process Tech 245：134-148，2017）中所示。本文通过改编的Norton-Hoff行为定律解决了材料参数的分散问题。然后，已使用标准的广义降梯度方法（GRG）确定了四个参数。此外，已经对整个轧制卷材进行了详尽的分析，以区分该材料所产生的变化与该工艺所产生的变化。这项研究还涵盖了应变速率对成形极限图的影响，因此也对成形极限应力图的计算产生了影响。