我厂在铸造某种铸件时;起初经常发生落砂和冷隔的现象,由于产品尺寸要求较高,因而使铸件大量报废,后来经苏联专家指导,改进操作方法,才基上消减这些缺陷。铸件的形状和主要尺寸如图1所示。在开始试造时,砂型和坭心均用车板制造,面砂和坭心砂用来陵砂20%和花四砂80%配合,另加1%糖浆,其湿压强度为0．4公斤/公分2,湿度7—8%。砂型面砂厚度将100~150公 When casting a certain kind of castings, our factory often had sand-falling and cold-separating phenomena at first. Due to the high requirement of product size, a large number of castings were scrapped. Later, the experts in Soviet Union improved their operation methods to reduce these defects. The shape and main dimensions of the casting are shown in Figure 1. At the beginning of the trial manufacture, both the sand mold and the heart were made from the car plate. The surface sand and the heart sand were used to mix 20% of tombstones and 80% of floridized sand with 1% syrup and the wet compressive strength was 0.4 Kg / cm 2, humidity 7-8%. Sand sand surface thickness of 100 to 150 public