The transient trajectory taken for a system striving toward equilibration has consequences on the rate of processes and on the chemical and physical state of products in metallurgical processes. A case study approach to recent advancements in liquid steel processing is given. A combination of techniques and knowledge developed is given as a targeted showcase of the authors’ contributions to the understanding of liquid metal droplet reactions and their contribution to the large-scale production processes within the steel industry. Examples relevant to novel ironmaking technologies, oxygen steelmaking, ladle metallurgy, and continuous casting are discussed, showing the range of processes that benefit from greater understanding in this area. This article considers specifically the reaction of liquid ferrous droplets, immersed in molten oxides, involving key alloying components, including phosphorus, aluminum, and carbon. The studies use high-temperature–confocal scanning laser microscopy (HT-CSLM), X-ray computed tomography (XCT), phase-field modeling, and in situ limited angle X-ray imaging. These techniques have seen significant development over recent years, and the combination of these powerful tools reveals the occurrence of spontaneous emulsification driven by chemical reaction (in the case of oxygen/phosphorus/aluminum reactions) and gas-phase formation (in the case of decarburization) both internally and externally to a steel droplet. A key finding is that the interfacial area pertinent for the heterogenous reactions to occur changes considerably (by up to an order of magnitude) depending on the chemical driving force. Additional key findings include the shift between preferential internal and external gas nucleation during decarburization, an inflection point of behavior as to whether or not spontaneous emulsification will occur (within the study discussed, this is between 3 and 4 wt pct Al) and the pathway of perturbation growth through which spontaneous emulsification occurs, including the physical maxima a perturbation will grow to before breaking away from the parent droplet.

中文翻译：

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液态金属加工中瞬态反应轨迹中的隐藏现象

力求平衡的系统所采用的瞬态轨迹会对过程速率以及冶金过程中产品的化学和物理状态产生影响。给出了钢水加工最新进展的案例研究方法。所开发的技术和知识相结合，有针对性地展示了作者对理解液态金属液滴反应的贡献及其对钢铁行业大规模生产过程的贡献。讨论了与新型炼铁技术、氧气炼钢、钢包冶金和连铸相关的示例，展示了受益于对该领域更深入了解的过程范围。本文专门考虑了液态亚铁液滴的反应，浸入熔融氧化物中，涉及关键合金成分，包括磷、铝和碳。这些研究使用高温共聚焦扫描激光显微镜 (HT-CSLM)、X 射线计算机断层扫描 (XCT)、相场建模和原位有限角度 X 射线成像。这些技术近年来取得了重大进展，这些强大工具的结合揭示了由化学反应（在氧/磷/铝反应的情况下）和气相形成（在脱碳的情况下）驱动的自发乳化的发生) 钢滴内部和外部。一个关键发现是，与发生异质反应相关的界面面积会根据化学驱动力发生显着变化（最多一个数量级）。