Run-out table bottom jet cooling

跳动台底部喷射冷却

• 批准号: 459359-2013
• 负责人: Militzer, Matthias
• 金额: $ 4.37万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=555562
• 关键词: Run; out; table; bottom; jet

There has been a tremendous development of advanced steels over the past few decades to provide steel products with improved properties for a wide range of applications including automotive, energy and construction. These advancements by steelmakers were critically enabled by design of innovative processing paths and better process control. Here, the development of process models has had a significant impact. For hot rolled steels cooling by water sprays on the run-out table is a key metallurgical tool to tailor the properties of the steel. During the cooling the phase transformation occurs 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 path, different transformation products can be obtained to create complex multi-phase microstructures which offer new paradigms for the design of properties. To realize this potential it is critical to control the cooling path precisely as this determines the phase transformation kinetics and the resulting microstructures. Cooling of hot moving steel sheets by water is a complex transient heat transfer problem including nucleate, transition and film boiling regimes. Current run-out table cooling models are to a large degree empirical in nature. There is a need to develop more fundamentally based models. Research in this area has so far emphasized top surface cooling whereas bottom jet cooling studies have received far less attention. Thus, the proposed project is designed to provide a systematic bottom jet cooling study to develop a cooling model for bottom jets that rigorously accounts for the underlying boiling mechanisms. The project is conducted in collaboration with ArcelorMittal Dofasco - Canada's leader in the production of automotive steel sheets. Experimental studies will be carried on a pilot scale run-out table facility to provide guidance for the model development. The proposed heat transfer correlations will then be incorporated into an existing hot strip mill process model of ArcelorMittal Dofasco such that the model can be validated with industrial data. The project offers training opportunities for three graduate students.

在过去的几十年里，先进的钢有了巨大的发展，为包括汽车、能源和建筑在内的广泛应用提供了性能更好的钢产品。钢铁制造商的这些进步在很大程度上得益于创新的加工路径设计和更好的工艺控制。在这里，流程模型的开发产生了重大影响。对于热轧钢材来说，在轧辊工作台上喷水冷却是调整钢材性能的关键冶金工具。在冷却过程中，从面心立方(Fcc)结构的奥氏体相转变为体心立方(Bcc)晶体结构的铁素体。具体来说，根据钢的化学成分和加工路径，可以获得不同的相变产物，以创建复杂的多相组织，这为性能设计提供了新的范式。要实现这一潜力，关键是精确控制冷却路径，因为这决定了相变动力学和由此产生的微观结构。热运动钢板的水冷却是一个复杂的瞬变换热问题，包括成核区、过渡区和气膜沸腾区。目前的台面冷却模型在很大程度上是经验性的。有必要开发更多基于根本的模型。到目前为止，这一领域的研究侧重于顶部表面冷却，而底部喷射冷却的研究则受到的关注要少得多。因此，拟议的项目旨在提供一项系统的底部喷射冷却研究，以开发一个严格解释基本沸腾机制的底部喷射冷却模型。该项目是与加拿大汽车薄板生产领先者安赛乐米塔尔Dofasco合作进行的。将在中试规模的流出试验台上进行实验研究，为模型的开发提供指导。然后，建议的热传递关联式将被并入安赛乐米塔尔Dofasco现有的热连轧过程模型中，以便该模型可以用工业数据进行验证。该项目为三名研究生提供了培训机会。