Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.
Experimental and numerical studies were carried out for the behavior of hydrogen in a three-phase electroslag furnace using double electrode series technique during electroslag remelting(ESR)process.The effect of water vapor content of furnace gas on the hydrogen content of ingots was studied through the"gas-slag-metal"osmosis experiment.Based on the experimental results,a mathematical model was set up for the behavior of hydrogen pick-up during ESR process.Then the flow of furnace gas during ESR process was studied through a commercial code FLUENT,and the relationship between the water vapor content of furnace gas and argon gas flux in practical production was derived.Finally,the desired reasonable argon gas flow for controlling the hydrogen content of ingots below 2×10-6 in practice was obtained.
