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内燃机车柴油机铸铁活塞的工作可靠性在很大程度上取决于铸件质量。这些铸件最普遍的铸造缺陷是缩孔、气孔、热裂,活塞铸件尺寸错误。缩孔的产生与铸件金属的不均匀冷却有关,这就导致合金在结晶后体积发生改变。气体形成源是活塞铸件体内缩孔形成的原因。型砂和型芯砂的水分偏高、透气性偏低和气化能力高是气体形成源。因铁水的个别一些成分的化学反应也会直接在铁水内产生气体。
The reliability of the diesel engine piston for diesel locomotives depends largely on the quality of the castings. The most common casting defects of these castings are shrinkage, porosity, thermal cracking, and incorrect size of the piston casting. The production of shrinkage cavities is related to the uneven cooling of the cast metal, which causes the volume of the alloy to change after crystallization. The source of gas formation is the cause of the formation of craters in the piston casting body. High sand and core sand moisture, low permeability and high gasification gas formation is the source. Due to the chemical reaction of some individual components of hot metal, gas will also be generated directly in the hot metal.