In this study, effect of temperature and time on melt-out of 25wt% Al-alloyed ductile iron has been investigated. The oxidation tests were carried out in a tube furnace at $800^circC$, $930^circC$, and $1000^circC$ for lh, 5h, 10h, 50h. The microstructure, microhardness, and $Al_2O_3$ layer of oxidation-treated 25wt% Al-alloyed ductile iron samples (10 x 10 x 10 mm) were investigated. Phase identification was performed by X-ray diffraction(XRD) and EDS. The oxidation-treated 25wt% Al-alloyed ductile iron samples at $930^circC$ for lh, 5h, 10h and KS GCD 500 were used for melt-out test in an Al alloy melt. The melt-out test results showed that oxidation tested sample at $930^circC$ for 5h which on the whole forms $2-3mum$ $Al_2O_3$ layer showed lowest melt-out depth. It was observed showed that appropriate Al203 layer can affect melt-out behaviors.