排气歧管熔模铸造充型和凝固过程数值模拟与优化

摘要

采用ProCAST铸造模拟软件对汽车排气歧管充型和凝固过程进行数值模拟.对原有生产工艺模拟表明,在冒口与底盘法兰的接触面处存在缩孔缺陷,工艺出品率较低,约为38.8％.模拟结果与实际生产情况吻合.优化工艺为:增大冒口尺寸,以增加冒日补缩距离;减小直浇道部位尺寸,将排气管移至直浇道顶部.模拟结果表明,优化工艺生产的排气歧管缩松缩孔明显减小,且缩孔全部集中于冒口部位,原底盘法兰处缺陷消失.同时,工艺出品率显著提高,由原来的38.8％提高到49.1％.%The ProCAST software was effectively used to simulate the mold filling and solidification process of the auto exhaust manifold.The results show that the porosity existed on the flange surface and the casting yield was low,which was in good agreement with the real production case.Based on the simulation results,the casting process of the exhaust manifold was optimized.The results show that the porosity on the flange surface was eliminated,and the casting yield was increased from 38.8％ to 49.1％.