Solidification structure simulation and casting process optimization of GCr15 bloom alloy

Based on the solidification heat transfer model and CAFÉ model, the solidification structure of GCr15 bloom alloy was studied. Using nail shooting and acid etching experiments, the solidification models were verified. The secondary dendrite arm spacing (SDAS) model of GCr15 was obtained by simulation calculation and metallographic observation. With the increase of casting speed, the SDAS, equiaxed crystal ratio (ECR) and average grain size increase. With the rise of superheat, the SDAS increases in the 20–70 mm of thickness and decreases in the 80–160 mm of thickness. The ECR decreases and the average grain size increases with the increase of superheat. With the increase of specific water flow, both the SDAS and ECR decrease. The minimum average grain size is obtained when the specific water flow is 0.20 L·kg^-1. The central carbon segregation index is reduced from 1.11 to 1.075.