液压泵壳体铸铁件粘砂的原因分析和对策

Analysis and Elimination of Sand Burning on Hydraulic Pump Case of Gray Cast Iron

分析了PVBQA泵壳体铸铁件粘砂的原因。通过采用较细的原砂，型砂中煤粉的加入量由2．5％增加到4．0％，新砂加入量由10％增加到30％，提高铸型的紧实度，浇注温度由1380℃降为1360℃等工艺措施，使铸件的粗糙度由Ra50μm降低到Ra25～12．5μm，消除了粘砂缺陷。

The sand burning on the PVBQA pump case of gray cast iron was firstly analyzed and some measures were taken. The compactness is improved by using finer mold sand, increasing the proportion of coal powder in the mold from 2.5 % to 40 % and increasing the proportion of new sand from 10 % to 30 %. The pouring temperature decreases from 1 380 ℃ to 1 360 ℃. The results show that the roughness of castings decrease from Ra50 μm to Ra25～ 12.5 μm and the defect of sand burning is eliminated.