Development of a New Mold Powder for Case Hardening Steel.

Recent years, automobile industry is strongly in need of the defect free steels in order to produce the lightweight and energy-saving cars. It is very important for satisfying this requirement to decrease the defects in continuous casting process. We developed a new mold powder for case hardening steel , which is the most sensitive steel grade to the surface cracks and depression on the casting bloom, in the view point of crystallization velocity to control heat transfer uniformly in the mold. The new mold powder has also good insulation property to decrease the slag bear and deckel, and makes it possible to achieve stable operation. In actual operation results,the fluctuation of temperature in the mold copper plate was quite small during casting and the surface defects on the casting bloom which originated in the initial solidification in the mold was