为了提高产量适合更大跃进的要求,我們将产量最多的电机端盖(如图1)由砂型铸造改为金属型鑄造。但在开始时铸件产生了白口(厚約3～4公厘)严重影响了鑄件質量。后来經过多次試驗,采取了一系列的措施,終于消除了白口,保証了鑄件質量。 鑄件产生白口的原因是:鑄件冷却速度太快;鉄水中碳、硅含量过 In order to increase the output for a larger leap forward, we changed the largest number of motor end caps (Figure 1) from sand cast to metal cast. However, at the beginning of castings produced white (about 3 to 4 mm thick) seriously affected the quality of castings. After many tests later, adopted a series of measures, and finally eliminate the white mouth, to ensure the quality of castings. Casting white reason is: casting cooling too fast; 鉄 water carbon, silicon content too