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从制芯材料、砂芯涂料、工艺间隙和浇注系统等角度研究了影响冷芯断裂的因素,对现有产品的断芯风险进行系统地分析和评估,并采取了相应的改进措施,得出以下结论:(1)原砂粒度在一定范围内分散只会增加芯砂的抗拉强度,不会造成其性能的削弱;擦洗砂和其它特种砂以合适的比例混合使用,可有效保证冷芯常温及高温强度,防止和减少断芯的产生.(2)在保证铁液相对平稳充型的条件下,浇注系统对断芯没有直接的影响.(3)根据产品具体结构,可以机动灵活地布置芯撑.另外,芯撑窝座及芯撑结构应考虑芯撑在铸型中的使用环境,在工艺设计阶段尽量避免使芯撑移位等问题.(4)形状复杂的砂芯在涂料、烘干及运输过程中应有合适的工位器具盛放及固定.(5)芯组与砂型配合间隙过小或过盈会造成砂芯机械断裂.(6)合适的推箱速度及缓冲可防止芯撑移位造成断芯.“,”The factors influencing the cold-box cores breaking rate was investigated in the respects of the core-making materials,cores coating,gaps between cores,gating system,et al.The cores breaking risk of existing castings was systematically analyzed and evaluated,and corresponding improving measures were adopted.The concludes were as followings:(1)The grain size separating distribution of base sand in a certain range could only increase the tensile strength,not cause weakening of other properties.Using scrubbed sand mixed with other special sand in a proper ratio could effectively guarantee normal temperature and high temperature strength of the cold-box cores and thereby could prevent and reduce cores-breaking.(2) Under the condition that the iron melt relatively stably filling mold the gating system had no direct influence on coresbreaking.(3)According to the configuration the cores chaplets could be deposed flexibly.In addition,the chaplets sockets and chaplets construction should be designed with considering the using environment of chaplets in the mold to avoid as possibly the chaplets moving and other problems during designing casting method.(4)There should be appropriate work place container to be used to contain complex shaped cores in their coating,drying and conveying processes.(5)Too small assemble gap between cores assembly and sand mold or interference would cause cores mechanical breaking.(6)Proper boxes-pushing speed and buffering could avoid chaplets moving and cause cores-breaking.