Speaker
Description
The electro-slag remelting (ESR) is a well-known process, which is widely used in the production chain of high-quality alloys. These alloys are used for many different applications ranging from tool steels to superalloys used in aero- or spacecraft applications. The process design is mainly unaltered since several decades. There only have been improvements regarding the process control and the input materials, as well as some developed derivatives of the process. Two ideas are currently discussed in the scientific community, of how to improve the ESR process, namely the use of a rotating or respectively a vibrating electrode. These approaches promise some significant process enhancements as well as some benefits regarding energy efficiency. There have been experimental and numerical studies made using these process modifications, potentially showing some of those beneficial effects regarding lab scale plants. The changing of the droplet size and trajectory as well as the metallic film thickness at the bottom of the electrode tip are significantly influencing these improvements. Numerical simulations can be used to predict certain influences caused by the scaling of the process. In this paper, we show different results for the simulated droplet formation in an ESR process with both a stationary and a rotating electrode using a coupled simulation between ANSYS Fluent and ANSYS EMAG. The results for low rotational speeds show a strong effect on the local shaping of the liquid metal film below the electrode and consequently a radial shift of the droplet incidence into the metal pool, but no significant effect on metal film thickness, droplet trajectory or droplet size. Furthermore, we are giving an overview of current bottlenecks, restrictions and possible strategies for improved process simulations.