AHSS:Development of Nano-acicular Duplex Steels

具有铁素体和奥氏体双重组织的先进高强度钢(AHSS)将被开发成类似于具有针状组织的高强度和抗断裂的钛合金。该项目组将处理贝氏体相变、相变增韧和直接计算铁固溶体物理性质等当前具有重要科学意义的问题。用高精度的第一性原理全势能线性化缀加平面波(FLAPW)方法对电子结构和晶格畸变进行了系统计算。理论计算将检验原子聚集和合金元素对轻杂质(C、N和B)漂移的影响。充分了解原子水平的性质将使我们能够设计具有更小规模的针状组织的钢，具有更高的强度和韧性。正在研究的先进高强度钢将有助于设计更轻、更省油的车辆，但通过提高耐撞性来保持乘客安全。与铝和其他轻质材料相比，这些新钢材将使钢材在性能和成本上保持竞争力。该计划将帮助招聘和培训个人在钢铁行业工作。钢铁行业一直是社会变革的一条途径。历史上很多？还是新的？美国人通过这个行业进入了中产阶级。我们希望延续这一传统，代表不足的群体将直接作为学生研究助理或通过在钢铁行业就业而成为这项研究的受益者。

Advanced high strength steels (AHSS) with duplex microstructures of ferrite and austenite will be developed analogous to high strength and fracture resistant titanium alloys that have acicular microstructures. The project team will address issues of current scientific importance with regard to bainitic phase transformations, phase transformation toughening and direct calculations of the physical properties of iron solid solutions. Systematic calculations of the electronic structure and crystal lattice distortions will be performed using the highly precise first-principles full potential linearized augmented plane wave (FLAPW) method. Theoretical calculations will examine atomic clustering and the effect of alloying elements on the drift of light impurities (C, N, and B). Full understanding of the atomic level properties will allow us to design steels with acicular microstructures on a smaller scale with greater strength and toughness. The advanced high strength steels under investigation will facilitate the design of lighter weight vehicles that are more fuel efficient, but maintain passenger safety with improved crash worthiness. These new steels will keep steel competitive both in performance and cost with respect to aluminum and other lightweight materials. This program will help recruit and train individuals to work in the steel industry. The steel industry has always been an avenue of social change. Historically many ?new? Americans gained entrance into the middle class through this industry. We expect to continue this tradition and under-represented groups will be benefactors of this research either directly as student research assistants or indirectly through employment in the steel industry.