φ738球面蜗轮(牌号TSnZnPbNi8－7－10－4)是我厂产品水泥车的一个主要零件,技术要求较高。在试生产过程中由于我们缺乏经验,开始时采用普通砂型铸造致使铸件产生成份偏析,同时由于采用高温浇注及其它不妥的工艺,致使铸件产生夹渣、缩松、气孔等缺陷,机械性能也达不到要求,铸件废品率高达90%以上。在“工业学大庆”的群众运动中, φ738 spherical worm gear (brand TSnZnPbNi8-7-10-4) is a major part of our factory cement truck, high technical requirements. In the trial production process due to our lack of experience, the beginning of the ordinary sand casting casting segregation caused by the composition, and due to the use of high temperature casting and other inappropriate processes, resulting in casting slag, shrinkage, porosity and other defects, mechanical properties Not meet the requirements, casting scrap rate as high as 90%. In the “Daqing Industrial” mass movement,