Variations of Mechanical Properties and Corrosion Rate with Melting Conditions and Alloying Elements in High Silicon Cast Irons

용해조건 및 합금원소 첨가에 따른 고규소 내산주철의 기계적 성질 및 부식속도의 변화

High silicon cast irons(HSCI) with the high acid resistance have been used for the prevention of acid corrosion occurring in various structures under acid conditions. However, the HSCI is only known as one of materials which have high acid resistance, but few work has dealt with this material in domestic. Therefore, in this study, the acid resistance of various cast irons with alloying elements and melting conditions have been examined, and studied the influences of the matrix structures, mechanical properties and morphologies of graphite. The results obtained in this study are as follows : In case of melting temperature, the mechanical properties of specimen manufactured with high temperature of $1650^{\circ}C$ showed higher value because the inclusion and impurity were removed. In case of pouring temperature, the mechanical properties of specimen fabricated below $1350^{\circ}C$ of pouring temperature showed higher value because the amount of gas absorption from atmosphere decreased during the solidification time. The corrosion rate decreased with increase in Si content. On the other hand, Mn addition appeared an opposite trend with Si.