| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To produce a bearing steel having high cleanness and excellent rolling fatigue life characteristic by using flux containing no fluorine source such as CaF<SB>2</SB>, thereby making inclusion in the steel fine and simultaneously reducing the number of the inclusions. <P>SOLUTION: Into a ladle for storing molten steel, CaO-SiO<SB>2</SB>based flux is added, then the molten steel deoxidized with Al and the flux are stirred by blowing a gas for stirring into the molten steel under atmospheric pressure, and after the total oxygen concentration in the molten steel becomes≤0.0030 mass%, Ca is added into the molten steel within the range in which [%CA]<SB>eff</SB>defined by the following expression (1) is 0.0003-0.0010 mass% and thereafter, the molten steel is refined under reduced pressure with a vacuum-degassing apparatus. (1) [%Ca]<SB>eff</SB>=[mass%Ca]-(0.18+130×[mass%Ca])×[mass%T.O], wherein [mass%Ca] denotes Ca concentration in the molten steel, and [mass%T.O] denotes total oxygen concentration (mass%) in the molten steel. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
