1 金属型湿砂型缩包铸球复合模具　专利号 :91 2 0 1 72 2 8此模具是一型多铸 ( 4～ 8个 )。与砂型铸球相比 ,具有组织致密、内外硬度均匀、工艺出品率高 (大于 75% )、废品率低(小于 5% )、铸铬系磨球省略高温处理等优点。平均吨球消耗模具费 30～ 50元。可向用户提供模具加 1 Metal wet sand type shrink cast ball compound mold patent number: 91 2 0 1 72 2 8 This mold is a type of more cast (4 ~ 8). Compared with sand casting ball, it has the advantages of compact structure, uniform hardness both inside and outside, high production rate (more than 75%), low reject rate (less than 5%) and high temperature processing of cast chromium grinding ball. Average tons of ball consumption mold costs 30 to 50 yuan. Can provide users with mold plus