The corrosion inhibition of magnetic iron powders by triazine dithiols

Abstract

The surface treatment of ultra fine magnetic iron powders with 6-substituted-1,3,5-triazine-2,4-dithiols (RTD) and their corrosion inhibition were investigated. The amount of RTD adsorbed was influenced by treating time and temperature, solvent, type of RTD and magnetic iron powder. Non-polar solvents and RTD with long alkyl chains in 6-substituted groups provided RTD films with a high layer number on the surface of the powders. Basic and Co-alloyed iron powders also had RTD films with a high layer number in the surface treatment of the powders. They showed lower corrosion rates than acidic magnetic iron powder. Magnetic iron powder changed to a mixture of Fe 2O 3 and FeOOH during aging in moist air. RTD treatment was very effective for preventing the corrosion of magnetic iron powder and decreasing its saturated magnetization. The preventive effect increased with RTD film thickness as well as water repellency and insulation. RTD treatment also prevented rapid exothermic reaction of iron powder in air.