轻量化是汽车节能、减排的关键，高比强度、高比模量材料是未来汽车轻量化的必然选择。正在研究的低密度、高强塑性Fe-Mn-Al-C系轻质钢，因Al元素的大量添加使其晶格点阵扩张、弹性模量明显降低，严重削弱了其低密度和高比强度的优势，制约其发展应用。基于Fe-Mn-Al-C系轻质钢可大量析出纳米κ-碳化物的特点及申请人前期研究发现，项目提出利用该轻质钢的纳米碳化物提高其模量，通过亚快速凝固扩大固溶极限增强析出、添加Cr元素改善基体和碳化物的模量、微合金化析出TiC纳米颗粒复合增强等措施，探索低密度、高强塑性和高模量的新一代高强汽车钢的设计基础。结合薄带连铸亚快速凝固的工业化应用平台，阐释亚快速凝固、时效处理时组织和纳米κ-碳化物的控制规律，揭示轻质钢组织、纳米碳化物特征和力学性能的关联与调控机制。项目选题有社会意义，材料研发思路有鲜明特色和创新性，探索高强汽车钢高效制备新工艺方面有显著的前瞻性。

For the energy crisis and environmental deterioration, the weight reduction of automobiles would be a natural direction to increase fuel efficiency and decrease CO2 emission. For the safety and stiffness of automobiles, gauge reduction will not be sustainable. The high specific strength/modulus materials would be the better selection for automobiles’ component. The Fe-Mn-Al-C light-weight steels with low density and high strength have attracted increasing attentions. But the expanding of the lattice parameter caused by high Al elements makes these light-weight steels clearly reduce in the elastic modulus. This detrimental effect would restrict their applications to automobiles in future. Based on the distinguishing feature that a large number of nano-carbides could precipitate from the Fe-Mn-Al-C light-weight steels, aim of this project is to improve the elastic modulus of light-weight steels by using the precipitated nano-carbides. In this project, expanding the solid solubility limit of near-rapid solidification will be used to enhance the nano-carbide precipitation, addition of Cr element is to improve the modulus of matrix and reinforced carbide particles, and TiC precipitated by microalloying method will be used to compound reinforce. These measures mentioned above will be made to develop a new generation of automobile steels those have the following characteristics such as low density, high specific strength/ modulus, and good ductility. Based on the twin roll thin strip continuous casting, an industry near-rapid solidification technology, this project will examine the relationship between the microstructures and mechanical properties of the light-weight steels solidified under near-rapid solidification conditions, and explore novel high-efficiency production process of advanced high strength steels. Study of this project would be very useful for energy-saving and emission-reduction.