Numerical Investigation on Solidification Shrinkage Behavior of P900 Hollow Ingot during Electroslag Remelting Process

A numerical model coupled with a multiphysical field based on a simple density‐based shrinkage model is established. After validation by comparing the experimental and simulation results, it is utilized to clarify solidification shrinkage behavior of electroslag remelting hollow ingot (ESR‐HI) process and investigate the effect of the inner mould taper angle and ingot withdrawing rate on air gap width and interfacial heat transfer coefficient (HTC). The interface between the hollow ingot and the inner mold can be divided into three regions, according to the change in heat transfer mechanisms. In region I, the inner wall and the inner mould are in complete contact, and effective HTC is maximum. In region II and region III, effective HTC decreases with increment in the air gap width. With increasing the inner mould taper angle and ingot withdrawing rate, solidification shrinkage at a given height of hollow ingot decreases. Moreover, it is reasonable that the inner mould taper angle is set to 1.5°, the distance from the slag‐metal interface to the bottom of the cylindrical section ( H cyl ) is set to 20 mm, and the withdrawing rate is set to 5 mm min −1 for P900 during ESR‐HI process with a cross‐sectional size of Φ300 mm/Φ100 mm.