| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a steel in which oxides are finely dispersed into molten steel and also, the steel material succeeding to the state is obtained. SOLUTION: The method for producing the steel is configured so that the molten steel is deoxidized by adding main deoxidizing elements selected from one or more kinds of Zr, Hf, Y and REM and the oxide-series inclusions of the main deoxidizing elements are dispersed. In the method for producing the steel, before adding the main deoxidizing elements, in the steelmaking temperature zone, the preliminary deoxidation is performed by adding a preliminary deoxidizing elements in which the affinity with oxygen is equal to or less than Al and stronger than Mn. Thereby, the oxide-series inclusions of the preliminary deoxidizing elements, generated and suspended in the molten steel, are made to be a solid phase in the steelmaking temperature zone, the concentration of this oxide-series inclusions in the molten steel is made to be 0.0005 to 0.01 mass% as the conversion of the oxygen concentration, and the respective concentration, in the molten steel, of the preliminary deoxidizing elements in equilibrium with the oxides of the preliminary deoxidizing elements are made to be equal to or less than the concentration in 5×10<SP POS="POST">-13</SP>to 1×10<SP POS="POST">-11</SP>atm of the oxygen partial pressure calculated with a deoxidizing reaction formula. Thereafter, the main deoxidizing elements are added to perform the deoxidation. COPYRIGHT: (C)2012,JPO&INPIT |
