Effect of Scale on Runout Table Heat Transfer

新型钢铁产品的开发继续对经济和社会做出重要贡献。钢铁发展速度的加快主要是由汽车工业的需求驱动的。在这里，先进的高强度钢材在减轻车辆重量方面发挥着至关重要的作用，从而提高燃油经济性，这是减少温室气体排放的一个关键方面。这些钢具有吸引人的性能，包括通过增加合金添加量（例如Mn， Si）和严格的工艺控制获得的卓越的强度-成形性平衡和耐撞性。热轧机跳动台上的冷却路径起着至关重要的作用，因为它可以用来调整从具有面心立方（FCC）晶体结构的奥氏体到具有体心立方（BCC）晶体结构的铁素体的相变。具体而言，根据钢的化学性质和加工工艺，可以设计由不同转化产物组成的复杂多相显微组织，这为性能设计提供了新的范例。特别是在高硅含量钢的热轧过程中，可能形成持久的氧化垢，影响跳动台上的冷却效率，导致不可接受的性能变化。因此，开发优化的跳动表处理策略来减轻规模的作用是很重要的。提出的项目旨在推进有关水垢对传热影响的基础知识。将进行专门的中试试验，以量化热萃取率，并采用先进的表征技术来确定水垢结构和化学成分。拟议中的项目是与加拿大领先的汽车钢板生产商ArcelorMittal Dofasco密切合作进行的，旨在为设计优化冷却策略提供新的见解。该项目为博士生提供了培训机会，他们将通过结合传热研究和微观结构表征来发展独特的技能水平。

The development of new steel products continues to be an important contributor in the economy and society. The increased pace of steel development is primarily driven by the demands of the automotive industry. Here, advanced high strength steels take a crucial role to reduce vehicle weight and thereby improving fuel economy as a critical aspect to decrease greenhouse gas emissions. These steels have attractive properties including superior strength-formability balance and crash worthiness that are obtained by increased alloying additions (e.g. Mn, Si) and stringent process control. The cooling path on the runout table in a hot mill takes a critical role as it can be used to tailor the phase transformation from austenite with a face-centred cubic (FCC) crystal structure to ferrite with a body-centred cubic (BCC) crystal structure. In detail, depending on steel chemistry and processing, complex multi-phase microstructures can be engineered consisting of different transformation products which offer new paradigms for the design of properties. In particular during hot rolling of steels with higher Si contents a persistent oxide scale may form that affects cooling efficiencies on the runout table leading to unacceptable property variations. Thus, it is important to develop optimized runout table processing strategies to mitigate the role of scale. The proposed project is designed to advance fundamental knowledge on the effect of scale on heat transfer. Dedicated pilot-scale runout table tests will be conducted to quantify heat extraction rates and advanced characterization techniques will be employed to determine scale structure and chemistry. The proposed project is conducted in close collaboration with ArcelorMittal Dofasco - Canada's leading producer of automotive steel sheets - and aims to provide new insight in designing optimized cooling strategies. The project offers training opportunities for a PhD student who will develop a unique skill level by combining heat transfer studies with microstructure characterization.