Influence of a rotating electrode on the droplet formation and the refining effect in the electroslag-remelting process

电渣重熔过程中旋转电极对熔滴形成及细化效果的影响

• 批准号: 309143753
• 负责人: Professor Dr.-Ing. Bernd Friedrich
• 金额: --
• 依托单位: Institut für Industrieofenbau und Wärmetechnik (IOB)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/309143753?language=en
• 关键词: Influence; rotating; electrode; droplet; formation

During the electroslag remelting process (ESR) a metal ingot is used as an electrode which is gradually molten in a slag layer. After passing through the slag layer, the molten metal solidifies in a controlled structure within a water cooled copper mold. During this process the metals degree of purity is improved by chemical and physical refining mechanisms. Compared to ingot casting less macro segregation can be observed, due to the smaller volume of liquid metal and the inductive stirring. Furthermore micro segregation is reduced, as the local cooling rates are fairly low. At the interface between slag and the copper mold a 1 to 3 mm thick slag skin solidifies. This layer reduces both the heat loss at the copper mold and the solidification rate in the metal pool.The present research project is focused on understanding fundamental mechanisms of removing non­metallic inclusions, the evolution of controlled columnar solidification and the formation of the slag skin. The insights gained will then be applied to a remelting process using a rotating metal electrode, which is a promising process innovation that has barely been investigated so far. Due to the centrifugal force acting on the liquid metal due to the rotation at the electrode surface, the size of metal droplets is reduced while the droplets specific surface and the residence time in the slag are increased.By carrying out experimental and numerical investigations understanding the refining mechanisms and non-metallic inclusion distribution is the objective of this study. This is to be achieved by examining the nickel based Alloy 718 targeting an improved degree of cleanliness and controlled solidification in a reproducible manner.

在电渣重熔过程（ESR）中，金属锭用作电极，在渣层中逐渐熔化。通过渣层后，熔融金属在水冷铜模具内以受控结构凝固。在此过程中，通过化学和物理精炼机制提高金属纯度。与铸锭相比，由于液态金属体积较小和感应搅拌，可以观察到较少的宏观偏析。此外，由于局部冷却速率相当低，微观偏析也减少了。在炉渣和铜铸型之间的界面处，1至3毫米厚的炉渣皮凝固。该层减少了铜结晶器的热损失和金属池的凝固速率。目前的研究项目的重点是了解去除非金属夹杂物的基本机制、受控柱状凝固的演变以及渣皮的形成。然后，获得的见解将应用于使用旋转金属电极的重熔工艺，这是一项有前途的工艺创新，迄今为止几乎没有被研究过。由于电极表面旋转而作用在液态金属上的离心力，金属液滴的尺寸减小，而液滴比表面积和在炉渣中的停留时间增加。通过进行实验和数值研究，了解精炼机制和非金属夹杂物分布是本研究的目的。这是通过检查镍基合金 718 来实现的，目的是以可重复的方式提高清洁度和受控凝固。