Macromechanical model for predicting the susceptibility to acid corrosion and hydrogen embrittlement of austenitic thin sheet metals and foils manufactured by complex forming technologies

尽管微观结构影响腐蚀行为，但腐蚀速率仅在少数情况下可以预测，并且根据现有技术水平，通过宏观力学FEM模拟无法充分获得。在先前的DFG项目AW 6/27-1/LA 1274/27-1中，发现材料DC 04和Al99.5的微观结构与表面腐蚀速率之间存在定性和定量的相关性。这些相关性实施到宏观力学有限元模拟。基于这些发现，本项目旨在扩展该模型在以下方面的适用性：（a）更复杂的材料（钢316 L），（B）氢脆，以及（c）薄金属箔（厚度< 0.5 mm）深冲的复杂多轴成形过程。为此，新的数学和物理为基础的概念以及数值方法将被导出并实施到FEM中。因此，第一次，材料316 L的腐蚀速率及其对氢脆的敏感性将是可预测的，这取决于已经受到成形影响的微观结构条件。因此，在由316L生产的双极板中，可以进行最佳微观结构和加工路线的数值计算。因此，对于在燃料电池中的应用，将实现改进的耐腐蚀性，并且将确保高效率的长使用寿命。

Despite the fact that the microstructure influences the corrosion behavior, corrosion rates can only be predicted in few cases and are insufficiently accessible by macromechanic FEM simulations according to the state of the art. In the previous DFG project AW 6/27-1/LA 1274/27-1, qualitative and quantitative correlations were found between microstructure and surface-corrosion rate for the materials DC04 and Al99.5. These correlations were implemented into a macromechanical FEM simulation. Based on these findings, the present project aims for expanding the applicability of the model with regards to (a) a more complex material (steel 316L), (b) hydrogen embrittlement, and (c) the complex, multiaxial forming process of deep drawing of thin metal foils (thickness < 0.5 mm). For this, new mathematically and physically based concepts as well as numerical approaches will be derived and implemented into the FEM. Hence, for the first time, the corrosion rate of the material 316L and its susceptibility to hydrogen embrittlement will be predictable in dependency of the microstructural condition that has been influenced by forming. As a result, in bipolar plates produced from 316L, numeric calculations of the optimum microstructure and processing route will be possible. Thus, an improved corrosion resistance will be achieved for the application in fuel cells and a long service life with high efficiency will be assured.