STUDIES ON THE PRESENCE OF COPPER IN THE GALVANIZED COATING ON WEATHERING STEEL AND THE ADHERENCE CHARACTERISTIC OF THE PROTECTIVE COPPER COMPLEX FORMED ON GALVANIZED WEATHERING STEEL

摘要

Following the hot-dip process for zinc coating on weathering steel, the galvanizing bath was found to have picked up copper. The galvanizing bath was observed to pick up Cu from the weathering steel at an average rate of 1.83 x 10(-3)% s(-1) m(-2) at 452 +/- 2 degrees C. EDAX/SEM studies exhibited a concentration gradient of copper to exist across the thickness of the galvanized coating on weathering steel. XRD studies revealed the formation of a protective copper complex, (CU[(OH)(2)Cu](3))SO4, on galvanized coating containing 0.739% Cu, when exposed in marine and industrial atmospheres. The adherence characteristic of the copper complex to the galvanized coating was found to be very satisfactory. [References: 7]