The influence exerted by phenylthiourea (PTU) on the corrosion process of Fe81B13.5Si3C2 metallic glass has been studied by recording the potentiodynamic polarization curves in deaerated 0.1N H2SO4 in the presence of various amounts (from 10-6 to 10-3 M) of PTU. The inhibiting action found on the glassy alloy has been compared to the corresponding one obtained on annealed Armco iron. Owing to its greater cathodic currents, the metallic glass corrodes faster than Armco iron, but PTU markedly decreases the severity of this attack. Phenylthiourea acts chiefly as an anodic inhibitor and its efficiency improves by increasing the concentration and testing time. The protective organic film forms more rapidly and is more stable on the amorphous alloy than on polycrystalline iron. A PTU concentration as low as 10-5M is sufficient to build an instantaneously efficient film on the metallic glass.
Effect of phenylthiourea additions on the corrosion of an iron-based metallic glass in 0.1N H2SO4 solutions
FRIGNANI, Alessandro;TRABANELLI, Giordano
2002
Abstract
The influence exerted by phenylthiourea (PTU) on the corrosion process of Fe81B13.5Si3C2 metallic glass has been studied by recording the potentiodynamic polarization curves in deaerated 0.1N H2SO4 in the presence of various amounts (from 10-6 to 10-3 M) of PTU. The inhibiting action found on the glassy alloy has been compared to the corresponding one obtained on annealed Armco iron. Owing to its greater cathodic currents, the metallic glass corrodes faster than Armco iron, but PTU markedly decreases the severity of this attack. Phenylthiourea acts chiefly as an anodic inhibitor and its efficiency improves by increasing the concentration and testing time. The protective organic film forms more rapidly and is more stable on the amorphous alloy than on polycrystalline iron. A PTU concentration as low as 10-5M is sufficient to build an instantaneously efficient film on the metallic glass.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.