Abstract
Background: The phenomenon of bronze disease is considered as the most important factor in the destruction of bronze objects. Different methods have been proposed to cope with it. The most important inhibitors used in this regard are BTA and AMT(5-ami- no-2-mercapto-1,3,4-thiadiazole). While these inhibitors control the corrosion, they are toxic and cancerous. In the ideal conditions, these inhibitors are able to slow down the activity of chlorine ion, but they leave some side effects after a period of treatment. Today, plant extracts are used for this purpose. In this study, Robinia pseudoacania L extract was selected for this purpose.Material and methods: Natural inhibitor of Robinia fruit at concentrations of 200 ppm to 1800 ppm was evaluated in a corrosive solution of sodium chloride 0.5 M on a bronze alloy with a percentage similar to ancient alloys (Cu-10Sn) using potentiostat, weight loss method, and humidifier area.Results: Given the data derived from potentiostate device showed that Robinia pseudoacania L Inhibitory power at 1000 ppm with corrosion rate of 12.78% is 55% and the classic method of weight loss inhibitory power after four week at 1800 ppm Robinia pseudoacania L in contrast a corrosive solution of sodium chloride 0.5 M is 92% for bronze alloy (Cu-10Sn). In addition, SEM images suggest that the formation of film on the coupon has been flacked. While the results of the analyses suggest the inhibitory power of Robinia pseudoacania L, granular corrosion is evident on the coupons surfaces in SEM-EDX(Scanning Electron Microscope-Energy Dispersive X-rays) images and analysis.Conclusion: According to the SEM-EDX method, the acetate potential device and the classical weight loss method on bronze (Cu-10sn), the results show that the corrosion rate in the acetate potential method is 55%, while in the classical method the reduction is shown. The weight of this figure reaches 92%. It is important to note that the SEM images show a kind of grain boundary separation on the coupons of this alloy, which is due to the presence of this substance in the corrosive solution of sodium chloride.
Microbial Corrosion of API 5L X-70 Carbon Steel by ATCC 7757 and Consortium of Sulfate-Reducing Bacteria
