汽车壳体铸件的铸造缺陷及成因分析

Analysis of Foundry Defects and Causes of Car Shell Castings

汽车壳体铸件在铸造过程中出现缺陷,导致废品率较高。对铸件缺陷取样并采用扫描电镜进行了形貌观察及能谱分析。结果发现,铸件中的缺陷主要是砂眼、氧化夹渣以及砂眼+氧化夹渣的复合缺陷,其缺陷的产生与浇注系统的设置、型腔内游离砂清除不干净、砂型强度较低、钢液中的炉渣去除不彻底有关。在采取优化浇注系统、彻底清除型腔内的游离砂粒、提高砂型强度、浇注系统中设置陶瓷过滤片等相关措施后,此类铸造缺陷发生率被控制在3%以下。

There are defects in the casting process of automobile shell castings,which leads to high scrap rate.The casting defects were sampled and analyzed by SEM.It is found that the defects in casting are mainly sand inclusions,oxidized slag and composite defects of sand inclusions+oxidized slag.The defects are related to the setting of gating system,unclean removal of free sand in cavity,low strength of sand mold and incomplete removal of slag in molten steel.After adopting the measures of optimizing gating system,thoroughly removing the free sand particles in the mold cavity,increasing the strength of sand mold,setting ceramic filter in the gating system,the incidence of such casting defects is controlled below 3%.