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夹砂缺陷形成的主要因素有两方面,一方面是型砂方面的因素,砂型在铁液热作用下,表面层水分向里层迁移,形成高湿度低强度层。表面砂层受铁液烘烤产生较大的膨胀压应力,如果型砂的热湿拉强度低、热压应力高就容易产生夹砂。另一方面浇注系统设计是否合理对夹砂缺陷的形成也有一定的影响。如果内浇道的位置设计不当,或流量不够而造成浇注时间过长,使铸型局部热作用剧烈,也容易产生夹砂。因型砂原
The main factors for the formation of sand inclusion defects are twofold: on the one hand, factors on the sand, and on the other hand, under the hot action of the molten iron, the surface layer of water migrates to the inner layer and forms a layer of high-humidity and low-intensity. Sand on the surface of the liquid baking baking have a greater expansion compressive stress, if the hot wet tensile strength of the sand is low, high thermal stress is easy to produce sand. On the other hand, the design of casting system is reasonable on the formation of sand-holding defects also have a certain impact. If the location of the runner is improperly designed, or the flow is not enough and the pouring time is too long, so that the local heat of the mold is violent, and it is easy to produce sand. Due to the type of sand