低密度微层状δ铁素体高强度高韧性钢板层状结构调控与断裂机理研究

高强度、高韧/塑性是钢铁材料发展的重要方向，调整钢铁材料的微观结构，使其成为微层状分布，可打破原本耦合在一起的材料性能，为同时提升材料的强韧性和使役性能提供有效途径。.项目提出利用高Al低密度高强钢中高温稳定δ铁素体，通过轧制变形控制成微层状分布，实现低密度、超高强度与超高韧性新型微层状钢铁材料的有机结合。项目将设计并制备出含有δ铁素体微层状结构的双相或多相高强韧钢，并对其特征层状结构进行定量调控，研究其变形断裂机理及力学性能特征，分析层片界面、尺寸及晶体学取向等结构参量对强度和断裂韧性的影响及内在相互关系，明确层状超高强韧钢中特征层状结构与力学性能之间关系，并研究其在苛刻工况条件下的腐蚀磨损行为。项目的研究，为深入理解微层状结构钢铁材料的强韧性本质及其断裂机理，探索新型高强高韧轻质钢制备和工业化生产陆地交通、航空航天和海洋运输等高端装备所需的高强度、高韧性低密度钢提供理论基础和数据支撑。

Steels have been keeping the development towards of high strength, high toughness and high ductility. Adjust the microstructure of steels to micro laminated structure can break the original coupling in material properties together, and significantly enhance the overall performance of the steel. This project intends to carry out research on preparation of high strength and high toughness low density steel with laminated microstructure of delta-ferrite by control the processes, and the fracture mechanism was also studied. The research will also focus on the coupling mechanism between feature lamina structure such as interphase, size and crystallographic orientation on strength and fracture mechanism. The relationship among the typical chemical composition, feature lamina structure and final mechanical properties will be established. We will prepare the high strength, high toughness/ductility and lamina structure controllable new steel plate in the lab, and analyze the crack initiation and propagation law of different thickness lamina layer and different grain size. This study will provide theoretical basis and data support for industrial production of high strength and high toughness steel which used for land traffic, aerospace and marine transport.