CORROSION-RESISTANCE OF VARIOUS MATERIALS IN MOLTEN-METAL

Corrosion resistance of various materials such as iron and steel, cerm et, cermet-coated steel, ceramics and ceramics-coated steel was evalua ted in molten zinc, molten aluminum-zinc alloy and molten aluminum at 470, 600, 700 degrees C, respectively. These temperatures are commonly used in continuous molten hot dip-plating line. The results are summa rized as follows: (1) All iron and steel samples tested were corroded in metal baths. But the corrosion amount was found to depend on sample composition and increased in the order Al > Al-Zn > Zn bath. Especial ly, the samples were severely corroded in the agitated Al bath. (2) Al l cermet and cermet-coated steel samples tested were corroded. Corrosi on amount varied with the composition of metal bath, composition and a mount of bonding metal for ceramic particles. (3) All ceramics and cer amics-coated steel samples tested were neither corroded nor markedly r eacted with molten metals. However, vanadium carbide film was partiall y crazed and peeled off when tested in the agitated Al bath.