2019 Pittsburgh AISTech

Inhibition Effect of CaO-ZrO2-C Nozzles on Alumina Deposition in Continuous Casting of Al-Killed Steel (Room 319)

06 May 19
3:00 PM - 3:30 PM

Tracks: Refractory Systems

Speaker(s): Masakazu Iida, Research Center, Shinagawa Refractories Co. Ltd.; Wei Lin, Shinagawa Refractories Co. Ltd.; Yukio Ohkawa, Shinagawa Refractories Co. Ltd.; Takayuki Matsunaga, Shinagawa Refractories Co. Ltd.

CaO-ZrO2-C (CZ-C) submerged-entry nozzles used in continuous casting of Al-killed steel for long casting times (500-1,000 minutes) were investigated. A thick Al2O3 clog deposit occurred on the Al2O3-C region of the nozzle inner wall, whereas no deposit formed on the CZ-C region. The CZ-C did not show any macrocorrosion either. The surface of CZ-C consisted of Al2O3-CaO phases forming the matrix (which were liquid at the casting temperature), ZrO2-CaO grains and Al2O3-MgO grains. This microstructure is considered to be formed by reactions between the CZ-C and molten steel and plays an important role in the alumina deposition inhibition.