Effect of Operating Conditions on Inclusion of Die Steel during Electroslag Remelting

Abstract

The current paper focuses on the effect of different operating conditions on the content of inclusions and cleanliness of remelting ingots. For these investigations, eight ingots were remelted with two slag amount and with two current intensity under otherwise comparable remelting conditions. A twodimensional (2D) coupled mathematical model was employed to simulate the velocity field, solidification and inclusion motion for a system of electrode, slag and ingot in electroslag remelting (ESR) processes, to reveal the inclusion removal mechanism. The results showed that the content of large-sized inclusions in ESR ingot was decreased by approximately 66.18% when the slag amount was increased from 17.85 kg to 20.50 kg. Because of the increase of slag amount, the metal and slag flow faster and the maximal velocity increases by 10.3%, thus there is an increasing trend in trajectories of inclusions (i.e., inclusion motion) in slag pool resulted from the stronger natural convective flow, which is beneficial for the inclusion removal. When the average current was increased from 4 kA to 5 kA, the content of large-sized inclusions in ESR ingot was decreased by approximately 51.38%. Because of the increasing of current, the flow in the middle of the slag pool becomes stronger and the maximal downward velocity increases by 2.7%, thus there is an increasing trend in the renewal rate of the metal film surface due to the stronger washing by slag flow, which can promote the inclusion removal.

Multi‐Stage Enhanced Removal of Inclusions During Electroslag Remelting Process by a Static Magnetic Field

“…These changes were also conducive to the inclusion removal in the LMF stage. As a result, the large-sized inclusions in the ESR ingot were significantly removed with increasing the remelting current in their study, [8] which is consistent with the experimental result in Figure 5b.…”

Untitled

“…Дослідники роботи [58] показали, що вміст крупних включень у зливку ЕШП штампової сталі Н13 залежить від умов ведення процесу, зокрема, він зменшився приблизно на 66,18 %, коли кількість шлаку збільшили з 17,85 до 20,50 кг. Крім того, при збільшенні середнього струму з 4 до 5 кА вміст великих неметалевих включень в зливку ЕШП H13 знизився приблизно на 51,38 %.…”

Numerical Simulation on Motion Behavior of Inclusions in the Lab-Scale Electroslag Remelting Process with a Vibrating Electrode

“…However, the formation and dripping of metal droplets were not considered in their work, which is one of the key methods for removing the inclusions. Du et al [10] established a 2D mathematical model to study the effect of different operating conditions on inclusions in remelted ingots of die steel based on experimental and thermodynamic methods. The results show that an appropriate increase in slag volume will lead to faster fluid flow of metal and slag, thus enhancing natural convection and strengthening inclusions movement to achieve better removal results.…”