Toughness of SAE 1020 steel with and without galvanization exposed to different corrosive environments in Chile

In this study, SAE 1020 steel Charpy's samples, with and without galvanization, were exposed to a large variety of environmental conditions throughout Chile in order to ascertain the degree of deterioration due to environmental corrosion. The levels of Cl^-, SO₂ and time of wetness were also registered in order to be able to correlate the data with respect to corrosion rate with the environmental and meteorological parameters. Calculations of corrosion rates were made via loss of weight and analysis of surface deterioration using scanning electron microscopy. After different exposure periods up to 33 months, the samples were tested and analyzed. According to the results, the toughness of the steel without galvanization can vary from 70 to 10 J; this variation reveals a dramatic change of property that is as much a function of the different atmospheres as of the exposure time. In comparison to the non-galvanized steel, the galvanized has a lower initial toughness, but it remains more constant over time, maintaining a range of 20 to 7 J.