Prediction On Temperature Of Liquid Steel During Process At Chongsteel

Stabilization of liquid steel temperature plays an important role in assurance of the smooth continuours casting operation in modern continuours casting production. Appropriate super heat of liquid steel is an important condition for high quality strand. Controling steel temperature effectivily is a key how to ensure the rhythm of production. So enhancing the level of controling the steel temperature from tapping, refining, then to casting process and stabilization of the liquid steel temperature should be important and valuable.According to combined with mathematic statistic and database, the law of temperature variation and the factors of temperature variaon during entire process were obtained by investigating the liquid steel temperature variation, tapping condition, temperature field of various ladle materials from tapping to casting process at Chongsteel. The relationship between the temperature and the factors of the temperature variaon was established, and the liquid steel temperature during the process can be predicted.Through thermal analysis of ladle, an idea that the heat is reduced with ladle wall was proposed. Whereas the round of permanent layer and the age of ladle are the main factors affecting heat-loss. The covering agent plays an important role in decreasing heat-loss of slag layer, but the ratio is only 4.41% of total heat-loss of ladle.Based on the measuring results for producation process at Chongsteel, the temperature drop of liquid steel for different steel grade and ladle situation is 8.74℃～72.42℃during tapping process. The temperature drop of liquid steel for different steel grade, ladle situation, round of permanent layer and age of ladle is in range of 6℃～16.16℃during blowing Ar process.The temperature increase range is 11.28℃～39.5℃during LF refining process. The temperature drop range is 12.61℃～19℃during waiting process. The temperature drop range is 28.9℃～39.8℃during casting process.The various formulas about the liquid steel temperature and the time affected by different factors from tapping to casting process were acquired by regression analysis. Based on B/S three layers architecture model, the prediction software system for liquid steel temperature was developed by combination tool of Windows2000, IISWeb, MS SQL Server2000 and ASP. The liquid steel temperature can be predicted by the software combined with mathematic statistic and database. Prediction error range is 0℃～±3℃. The hitting ratio range error under 1.5℃is 83.3%. The hitting ratio range error under 2℃is 94%. So the method can predict the liquid steel temperature accurately.