Role of graphite nodules on the corrosion behavior of ductile iron in molten aluminum
Ruiqi Chu, Yuzhou Du, Xuefeng Zhao, Qi Zheng, Chao Yang, Bailing JiangPurpose
This study aims to elucidate the role of graphite nodules in the corrosion behavior of ductile iron in molten aluminum and to provide references for the design of Al alloy die-casting molds.
Design/methodology/approach
Ductile irons with different graphite nodule counts were fabricated and immersed in molten aluminum for various durations. The corrosion behavior of ductile iron in molten Al was evaluated by characterizing the morphology, phase constituents and thickness of intermetallic compound (IMC) layers formed at the interface.
Findings
The IMC layer is primarily composed of FeAl3, Fe2Al5 and Fe-Al-Si phases, with Fe2Al5 governing the overall layer thickness. As the number density of graphite particles increases, the thickness of IMC layer formed in ductile iron decreases. When graphite nodule count exceeds 600/mm2, the corrosion resistance of the ductile iron surpasses that of H13 steel.
Originality/value
Reduced internodular graphite spacing significantly enhances the resistance of ductile cast iron to molten aluminum corrosion, while graphite nodule size should also be comprehensively considered. This finding provides a reliable reference for the design of aluminum alloy die-casting molds. The present finding provides reference for aluminum alloy die-casting die design.