Effect of pigmentation on mechanical and anticorrosive properties of thermally sprayable EVA and EVAl coatings
By Tambe, S.P.; Singh, S.K.; Patri, M. & Kumar, Dhirendra
Published in Progress in Organic Coatings
2011
Abstract
In this paper, the sensitization of aged Incoloy 800 alloy to intergranular corrosion has been systemically investigated by double loop electrochemical potentiokinetic reactivation (DL-EPR) technique in combination with oxalic acid etching test and microstructure observation. The DL-EPR results show that the specimens aged at 650 °C and 700 °C for 4 h were intensely sensitized with Ir:Ia value greater than 30% while there was no sensitization phenomenon for the specimens aged at 800 °C for 4 h. It was also found that the degree of sensitization increased gradually with the aging time in the range of 0–10 h at 650 °C, and Ir:Ia value reached the maximum -46% after an aging time of 10 h. However, further increasing aging time decreased the sensitization due to the healing effect incurred by the diffusion of chromium from adjacent grains to chromium-depleted zones. Comparison between two evaluating techniques (the DL-EPR and oxalic acid etching test) has also been conducted.