| 摘要 |
<p>The invention relates to a powder product for protecting centrifugal casting molds of cast iron pipes, dry-projected onto a first wet-spray layer, comprising constituents common to dry-spray products with exception of CaSi alloys, as well as a wet-spray additive serving to ensure the adhesion to the pipe, during its removal from the mold, initially applied to the permanent mold. Said additive can be an alkali carbonate or alkali silicate, for example, sodium silicate in which the ratio of the wt. % of SiO<SUB>2</SUB> to that of Na<SUB>2</SUB>O varies from 1 to 3, or anhydrous sodium metasilicate as well as a mixture consisting of one or more thereof in any proportions.</p> |
