Simulation of critical interface phenomena in advanced steel processing

最先进的钢铁加工模型是基于微观结构工程的概念，其中工业过程的操作参数通过精确模拟微观结构演变与钢铁产品的最终性能相关联。对大多数钢来说，奥氏体-铁素体相变是调整性能的关键冶金工具。包括原子场和相场模拟在内的多尺度方法有望推进钢的相变模型。相场模型是一种强大的方法来描述具有复杂形态的显微组织的演变，这在高级钢中很常见。因此，相场模型被提出作为一种有前途的计算工具，用于开发从铸造到最终热处理的下一代过程模型。拟议的发现项目将寻求进一步探索和发展相场方法的基础，作为先进钢铁加工的模拟工具。特别是，将开发先进的计算方法，将原子模拟结果纳入晶粒生长和奥氏体-铁素体相变的相场模型。在这里，迁移界面与合金元素的相互作用起着中心作用，原子模拟可以为这些相互作用机制提供新的见解。对于高性能热轧钢来说，加速冷却已成为控制相变及其性能的关键技术。莱顿弗罗斯特温度是一个关键的冷却参数，从膜沸腾过渡到更有效的冷却机制，包括核沸腾发生。莱顿弗罗斯特温度在很大程度上取决于表面粗糙度。这是另一种界面现象，相场模型可以提供强大的仿真技术。****提出的研究中一个令人兴奋的组成部分是对微观结构和温度演变使用相同的建模框架。本研究为培养3名博士研究生提供了机会。前两个博士项目将寻求将溶质界面相互作用的原子模拟结果纳入相场模型。第三个项目将涉及相场模型的发展，以解释表面粗糙度对钢冷却的影响。******************

State-of-the-art models for steel processing are based on the concept of microstructure engineering where the operational parameters of the industrial process are linked to the final properties of the steel product by accurately modelling the microstructure evolution. For most steels the austenite-ferrite transformation is a key metallurgical tool to tailor the properties. A multi-scale approach including atomistic and phase field simulations has shown promise to advance phase transformation models in steels. Phase field modelling is a powerful methodology to describe the evolution of microstructures with complex morphologies that are common in advanced steels. Thus, phase field models are proposed as a promising computational tool for developing next generation process models from casting to final heat treatments. The proposed discovery project will seek to further explore and develop the fundamentals of the phase field methodology as a simulation tool for advanced steel processing. In particular, advanced computational approaches will be developed for incorporation of atomistic simulation results into phase field models for grain growth and the austenite-ferrite transformation. Here, the interaction of migrating interfaces with alloying elements plays a central role and atomistic simulations can provide new insight into these interaction mechanisms. For high performance hot-rolled steels accelerated cooling has become a key technology to control the phase transformation and resulting properties. The Leidenfrost temperature is a critical cooling parameter where the transition from film boiling to more efficient cooling mechanisms including nucleate boiling occurs. The Leidenfrost temperature depends significantly on surface roughness. This is another interface phenomenon where phase field models may provide a powerful simulation technique.****An exciting component of the proposed research is to use the same modelling framework for both microstructure and temperature evolution. The proposed research offers opportunities for training of three PhD students. The first two PhD projects will seek to incorporate atomistic simulation results for solute-interface interactions into phase field models. The third project will deal with the development of a phase field model to account for the effect of surface roughness on cooling of steel.******************