| 摘要 |
PURPOSE:To extend the service life of a cover by containing silicon nitride in the cover material as main component, adding and mixing little quantity of adding agent and the other component and successively, executing sintering to form the cover as sintered body. CONSTITUTION:In the cover material containing the silicon nitride as the main component, a small quantity of the components alumina, yttria, etc., and binder, etc., are mixed and formed, and the sintering is executed at the prescribed temp., to form a sensor cover as the sintered body. As the silicon nitride originally has bad wettability with molten metal, sticking of the molten steel to the sensor cover formed with alumina binder as refractory is restrained, and as it is formed as the sintered body, heat impact resistance for the cover itself is improved. By this method, the service life of the sensor cover in the case of using it in the molten steel is remarkably extended. |
