Effects of Process and Casting Variables on the Results of Degassing AC4C Aluminum Alloy Melt by Using Rotary Degasser

공정 및 주조 변수의 AC4C 알루미늄 합금 용탕의 로터리 degasser를 이용한 탈가스 처리 결과에 미치는 영향

The effect of various factors on the results of degassing of AC4C aluminum alloy melt by using rotary degasser were investigated. The difference between the effects of nitrogen gases of commercial pure and high purity grades on the degassing results was not significant. The optimum degassing condition was obtained. The effect of holding and degassing temperature was not significant, either. The result of degassing was deteriorated by the modification treatment of eutectic silicon, meanwhile improved by the grain refining. The effect of the latter was stronger than that of the former when the melt was treated simultaneously. The volume fractions of hydrogen porosity of the castings obtained from the molds with water moisture such as natural and green sand molds were much higher than those from the molds without that such as pep-set and $CO_2$ molds.