Corrosion behaviour of steel/55%Al–Zn alloy/paint systems exposed to natural and artificial environments

Abstract

The corrosion performance of steel/55%Al–Zn alloy sheets pre‐treated with 5% Fe (NO3)3 + 15% H3PO4 solution, and then coated with acrylic (AC), alkyd (AQ), vinyl (VL), solvent‐based epoxy (ES) or waterborne epoxy (EA) corrosion‐inhibiting primers + a barrier topcoat alkyd paint was studied. Exposure conditions included weathering chambers and natural atmospheres (La Plata‐Argentina and San Luis‐Potosí, México). The panels' behaviour was evaluated through visual inspections and EIS measurements. Their results allowed inferring that: (1) most of the painting systems have a satisfactory performance during their exposure to the accelerated weathering chamber or the natural atmospheric stations and (2) the correlation between them allowed explaining some problems arising in service. This information will allow extending the useful life by adjusting the painting system formulation.

Galvanic corrosion of aluminum–steel under two-phase flow dispersion conditions of CO2 gas in CaCO3 solution

“…The galvanic corrosion rate and the potential distribution over a galvanic couple are, in general, dependent upon the electrochemical properties of the metals, on environmental variables such as temperature, salinity, oxygen content, and solution flow, as well as the geometry of the corroding system. If dissimilar materials can be coupled without significant damage, a greater flexibility in the material selection may be possible (Varela et al, 1997;Zhang, 2011;Elsner et al, 2014).…”

A conversion layer based on trivalent chromium and cobalt for the corrosion protection of electrogalvanized steel

“…In industrial practice, the corrosion resistance of coated materials is usually evaluated using accelerated tests such as salt spray [47], Kesternich test [48] or saturated humidity chamber [49]. However, in the last decades, EIS has also been proven to be a useful tool to evaluate the corrosion resistance of coated metals [50][51][52][53].…”