Simulation of critical interface phenomena in advanced steel processing

最先进的钢加工模型基于组织工程的概念，通过精确地模拟组织演变，将工业过程的操作参数与钢产品的最终性能联系起来。对于大多数钢来说，奥氏体铁素体转变是调整其性能的关键冶金工具。一种包括原子模拟和相场模拟在内的多尺度方法显示了改进钢中相变模型的前景。相场模拟是描述先进钢中常见的具有复杂形貌的组织演变的一种强有力的方法。因此，相场模型被认为是开发从铸造到最终热处理的下一代过程模型的一种很有前途的计算工具。拟议的发现项目将寻求进一步探索和发展相场方法的基本原理，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，将原子模拟结果合并到相场模型中，用于晶粒生长和奥氏体-铁素体相变。在这里，迁移界面与合金化元素的相互作用起着核心作用，原子模拟可以为这些相互作用机制提供新的见解。对于高性能热轧钢材，加速冷却已成为控制相变和性能的关键技术。莱登弗罗斯特温度是从膜沸腾向包括核沸腾在内的更有效的冷却机制转变的关键冷却参数。莱登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模拟技术。 拟议研究的一个令人兴奋的部分是对微观结构和温度演变使用相同的建模框架。这项拟议的研究为培训三名博士生提供了机会。前两个PHD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。第三个项目将处理相场模型的开发，以考虑表面粗糙度对钢的冷却的影响。

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.