关键词: 高强度不锈钢, 真空自耗重熔, 成分偏析, 数值模拟, 均匀化

Abstract: Melt flow-VAR simulation method was used to study the effect of melting rate on the molten pool shape and macro segregation of low-cost corrosion-resistant high-strength stainless steel ingot during vacuum arc remelting， the morphology of molten pool changed form "shallow flat" to "U-shap"， and finally to "deep V-shap"， with the increasing of melting rate from 3.2 kg /min to 6.2 kg /min and the metal pool volume was gradually increased. The depth of molten pool increased from 120 mm to 175 mm with increasing the melting rate from 3.2 kg /min to 5.2 kg/min. When the melting rate exceeded 5.2 kg/min， the time to reach steady state was extended， the proportion of ingot cylindrical crystals increased， and the segregation degree of alloying elements was intensified. 4.2 kg /min was determined as the actual melting rate， the mushy zone width was narrow， and the molten pool depth was 140 mm in the stable melting stage. The metallurgical quality of the ingot remelted at 4.2 kg/min was evaluated， the alloy compositions at different positions of the ingot at the said melting speed had good uniformity， the result of macrostructure inspection showed that there was no obvious macrostructure defects in the ingot. After homogenization at 1 220 ℃ for 4 h， the micro segregation of C， Cr， Ni and Mo elements in the steel was significantly improved .

Key words: High-strength Stainless Steel, Vacuum Arc Remelting, Composition Segregation, Numerical Simulation, Homogenization