Ladle shrouds (LS) and SEN are mainly constructed of alumina-graphite (AG) materials, and recently carbon-free (CF) materials are utilized for the inside liner. The CF inside liner has some superior characteristics for casting clean steels however one major challenge is thermal spalling due to high thermal expansion. The CF liner acts as a heat insulator reducing thermal shock due to its low thermal conductivity. Therefore when thermal expansion is reduced to a certain level, the CF liner is expected to improve thermal-spalling resistance of the LS and SEN. Through an investigation on various materials, we have developed the CF materials with relatively low thermal expansion. The effect of thermal expansion and conductivity on the thermal stress of the LS is evaluated by FEM. Conventional CF materials cause large thermal stress compared to LSs without CF liners. However, low thermal-expansion CF materials reduce thermal stress at the neck through a heat-insulation effect, reducing uneven temperature distribution.
展开▼
