Defects generated during the casting process of steel can be reduced by forming processes such as hot rolling. During these processes the effective strain, the temperature, the stress state and the alternation of the forming direction all influence the defect evolution. Analytical or numerical models are available in the literature to predict the defect evolution. However, experiments have to be carried out to identify the parameters of these models. Thus, the quality of the identification depends on the representativeness of the experiments with respect to the industrial forming process. This paper proposes a methodology to design reduced scale experiments with an improved level of representativeness. This methodology consists first in the identification of the thermomechanical parameters driving the defect evolution and the quantification of these parameters in the industrial process by FEM simulation. These last results are then utilised as criteria for the representative experiment design. In this work the methodology is applied to the rolling of bars. The representative experiment consists of successive forming operations of a cylindrical sample between shaped anvils reproducing the roll shape at a 1:10 scale. A validation is finally achieved by reproducing qualitative results concerning the evolution of voids in the vicinity of hard inclusions.

中文翻译：

---

基于FEM的缩小尺寸代表性实验测试设计方法，可表征棒材热轧过程中的缺陷发展

可以通过诸如热轧之类的成形工艺来减少在钢的铸造过程中产生的缺陷。在这些过程中，有效应变，温度，应力状态和成形方向的交替都会影响缺陷的发展。文献中提供了分析模型或数值模型来预测缺陷的发展。但是，必须进行实验以识别这些模型的参数。因此，识别的质量取决于有关工业成型过程的实验的代表性。本文提出了一种方法，以设计具有提高的代表性的缩小规模的实验。这种方法首先包括确定驱动缺陷发展的热机械参数，并通过有限元模拟对工业过程中的这些参数进行量化。然后将这些最新结果用作代表性实验设计的标准。在这项工作中，该方法学应用于钢筋的轧制。代表性的实验包括圆柱状样品在成形的砧座之间的连续成型操作，这些砧座以1:10的比例重现了辊的形状。通过重现有关硬质夹杂物附近空洞演变的定性结果，最终实现了验证。在这项工作中，该方法学应用于钢筋的轧制。代表性的实验包括圆柱状样品在成形的砧座之间的连续成型操作，这些砧座以1:10的比例重现了辊的形状。通过重现有关硬质夹杂物附近空隙演变的定性结果，最终实现了验证。在这项工作中，该方法学应用于钢筋的轧制。代表性的实验包括圆柱状样品在成形的砧座之间的连续成型操作，这些砧座以1:10的比例重现了辊的形状。通过重现有关硬质夹杂物附近空洞演变的定性结果，最终实现了验证。