Optimizing the Bendability of Advanced High Strength Steels for Automotive Applications

该项目旨在提高ArcelorMittal Dofasco在北美汽车供应链中先进高强度钢板的竞争力。它通过解决大多数汽车oem和零部件供应商施加的关键材料验证要求来实现这一目标，即通过标准测试测量钢材具有足够的可弯曲性。随着汽车工业转向使用更强的钢材，从而使车辆重量减轻，它必须容忍随之而来的延展性降低。这限制了材料的可弯曲性。开发满足这些严格要求的材料需要对控制板材可弯曲性的微观结构参数有深入的了解。此外，如果可以在可弯曲性和可在标准拉伸试验中测量的性能之间建立明确的联系，则开发的新材料将得到加强。该项目将使用一系列复杂的原位和非原位方法，通过详细的拉伸和弯曲损伤和断裂实验研究来实现这两个目标。感兴趣的材料是一系列钢，所有钢的标称强度都为980兆帕，但其潜在的微观结构却截然不同。实验结果将为底层微观结构和可弯曲性之间的关系提供一个强有力的理解。然后，这些数据将被用作多维宏观-微观模型的输入，根据微观结构和拉伸测试性能的知识，该模型将预测可弯曲性。

This project aims to improve the competitiveness of ArcelorMittal Dofasco within the North American automotive supply chain for advanced high strength steel sheet. It does so by addressing a key materials validation requirement imposed by most automotive OEMs and parts suppliers, namely that the steel offer sufficient bendability as measured by standard tests. As the automotive industry moves towards the use of stronger steels, thereby enabling vehicle weight reduction, it must tolerate the concomitant reduction in ductility. This limits the bendability of the material. Developing materials that meet these stringent requirements requires a robust understanding of the microstructural parameters that control sheet bendability. Moreover, new materials developed will be enhance if a clear link can be drawn between bendability and properties that can be measured in a standard tensile test. This project will address both goals through a detailed experimental study of damage and fracture in both tension and bending, using a sophisticated array of in-situ and ex-situ approaches. The materials of interest are a range of steels, all with a nominal strength of 980 MPa but with very different underlying microstructures. The experimental results will provide a robust understanding of the relationship between the underlying microstructure and bendability. The data will then be used as input into a multi-dimensional macro-micro model from which bendability will be predicted based on a knowledge of the microstructure and tensile test properties.