先进高强钢的使用是汽车实现轻量化并兼顾安全性的必由之路。为了促进超高强度Q&P钢、中锰钢和热成形硼钢在汽车上的应用与推广，需要深入理解这些超高强度钢的动态力学行为，并评价其汽车零件的服役安全性。因此，本项目拟解决下列关键的科学与技术问题：（1）深入理解这些超高强度钢的动态力学行为，以及动态力学行为背后的微观机理，特别是应变率和温度耦合对动态力学行为和微观组织演变的作用规律；（2）建立数值模拟所需的包含应变速率和温度影响、微观组织演变信息的物理本构模型，以及断裂准则；基于此物理本构模型和断裂准则模拟超高强度钢零件的碰撞过程，并评价其碰撞安全性；（3）深入研究这些超高强度钢的氢脆敏感性及其微观机理，建立其发生氢致延迟断裂的可扩散氢含量-应力临界条件；评价超高强度钢零件的氢致延迟断裂风险。

The use of advanced high-strength steels is an effective way to reduce the weight of vehicles while guaranteeing passive safety. In order to promote the application of ultrahigh-strength Q&P steel, medium-Mn steel and hot-stamped boron steel on automobiles, it is critical to understand their dynamic deformation behavior as well as to evaluate the service performance of components made of these steels. Therefore, the present project intends to solve the following critical scientific and technological problems related to these steels: (1) to understand their dynamic deformation behavior and the underlining physics, especially the effects of strain rate and temperature on the stress-strain relations as well as the microstructure evolution; (2) to develop their microstructure-based constitutive laws which take into account the effect of strain rate and temperature; to establish their fracture criteria and to evaluate their crash performance; (3) to study their hydrogen embrittlement behavior and the underling physics; to evaluate their delayed fracture behavior based on their critical hydrogen-stress conditions.