Thermodynamic analysis of decarburization and chromium preservation of stainless steel in oxygen blowing process of VOD

In order to ensure high decarburization and high recovery rate of chromium in the VOD oxygen blowing stage, the influence of oxygen supply, temperature and vacuum degree on the carbon and chromium content of ZG06Cr13Ni4Mo stainless steel during the oxygen blowing process of VOD were calculated by FactSage8.1. And orthogonal experiments were carried out to determine the order and optimal value of oxygen supply, temperature and vacuum degree on decarburization and chromium preservation. These results show that the oxygen supply in the oxygen blowing stage should be controlled within the range of 4.68-6.10 m³/t (normal). The temperature of blowing oxygen should be set within 1 585-1 600 ℃ and the temperature of stopping blowing oxygen should not exceed 1 750 ℃. The pressure ought to be controlled within 5-9 kPa. Based on the orthogonal experiment, the results indicate that the factor of oxygen supply has the greatest impact and followed by vacuum, then temperature. The optimized conditions are oxygen supply of 4.9 m³/t (normal), temperature of 1 600 ℃, and pressure of 7 kPa, respectively. Under this condition, the carbon mass fraction and chromium mass fraction are 0.027% and 12.201%, respectively.