Corrosion resistance of light gauge steels for steel framed house

Atmospheric corrosion on the inhabited steel framed house was investigated with Fe-Ag galvanic type atmospheric corrosion monitoring (ACM) sensors. As the environmental conditions, temperature, humidity and currents of the ACM sensors were continuously measured in several parts of the house for five years. Corrosion rates of hot-dip galvanized steel sheet, Zn-5%Al coated steel and 55%Al-Zn coated steel for the light gauge steels were also determined on the basis of exposure tests. Service life of the galvanized steels and dew condensation in the house were discussed. Amount of deposited sea salt influences the corrosion resistance of the coated steels. Under the indoor conditions of the inhabited house, the amount of deposited sea salt was negligibly small. It is difficult to evaluate the corrosion resistance of coated steel sheets using convenient corrosion tests because of too much sea salt.