Investigation On The Cleanness Of HP295 Steel Produced By BAr-CC Production Route

With the widely application of billet, its quality requires be improved. The nonmetal inclusion harmness has received more attention. Therefore, the controlling of the quantity, shape and distribution of inclusion are essential to ameliorate the quality of steel.Based on the literature summarization, experimental study and investigation of present production of billet,the investigation of inclusions in HP295 steel has been carried out in BAr-CC system of WISCO. Samplings from different procedures have been analyzed by means of metallographic examination, Scanning Electron Microscope (SEM) and chemical analysis, etc.The main conclusions are drawn as follows: The Ar blowing caused the decreasing of T[O] and increasing of quantity effectively; the effect of removing inclusion is not good, so further performance of the metallurgy between ladle and tundish is required; the occurrence of absorbing [N] and the second oxidization during each process degraded the cleanness of the steel; the steel cleanliness is very regularly, the peak of the inclusions is appeared in the 1/4 thickness of the inside direction,but it is average on the width direction.According to the researches, in order to obtain HP295 steel of high quality, the followings are some measurements and suggestions: optimizing the operation of Ar blowing to help the floating of the inclusions; strengthening the protective casting to avoid the second oxidization; taking rare earth treatment or alkaline-earth metals treatment to improve the distribution and the morphology of inclusions.