PURPOSE: To decrease the reverse V segregation, top segregation, hole type defects, etc. of a thin-walled steel ingot and to improve the yield thereof by forming a casting mold for a specified weight or about of the flat steel ingot into a specifically sized shape which is large in the wall thickness of the lower part and has a specified rate or below of an upwardly expanding taper.
CONSTITUTION: The sized and shape of the casting mold for ≥30t flat steel ingot are specified to the specific relations expressed by the equation IW equation IV, where M: the own weight of the casting mold, I: the own weight of the steel ingot, H: the height of the casting mold, D: the average thickness of the steel ingot, W: the average width of the steel ingot, D1: the distance between the top ends on the long side surfaces of the casting mold, D2: the distance between the top and bottom end thereof, d1: the wall thickness at the top end on the long side surface of the casting mold, d2: the wall thickness at the bottom end of said top surface. The steel ingot is made thin film if the casting mold is formed to such size relations. The wall thickness of the casting mold is made thinner toward the lower part and the upwardly expanding taper quantity is kept at ≤2% by which the reverse V segregation and top segregation are decreased and the vertical distribution of C is made uniform. The hole type defects are decreased and the yield of the good steel ingot is improved. In addition, the cost of heating and rolling is decreased.
MATSUKAWA TOSHITANE
TACHIBANA RINZO
SHINJO YUTAKA
KORIYAMA TAKESHI
| JPS60130448A | 1985-07-11 | |||
| JPS6033852A | 1985-02-21 |