Comparación del rendimiento de tres métodos de protección anticorrosiva y estimación de la velocidad de corrosión según la Norma ASTM G1-03 en placas de acero ASTM A36

Abstract

The objective of this study was to compare the performance of three anticorrosion protection methods and estimate the corrosion rate according to the ASTM G1-03 standard in ASTM A36 steel plates. The applied methodology follows the procedure established in the ASTM G31-21 and ASTM G1-03 standards. While a chemical solution based on the ASTM G44 standards was used for corrosion. The corrosion rate was carried out by calculating the optimal sample size of the number of steel witness plates A36 to be immersed in a 3.5% sodium chloride solution, placed in 4 polypropylene vats, simulating the corrosive environment under conditions containing a pH between 6-7 and a temperature between 25-30ºC. For the first method, a polymeric coating was applied according to the SSPC-PA 1 standard using high volume solids epoxy paints with a corrosion rate of 0,0502 mm/year. In the second method, cathodic protection was applied by sacrificial anode on the witness plates obtaining a speed of 0,0275 mm/year. The third method used a sacrificial anode by impressed current in which an external source was used to circulate current between the anode and cathode, resulting in 0,0096 mm/ year. It is concluded that the optimal method to combat corrosion is cathodic protection by sacrificial anode. Compared to other methods, its performance and implementation cost, it is the lowest since its application has an approximate value of 0,12 USD/ cm2 and its average corrosion rate is 0,0275 mm/year. It is recommended that polymers be used directly on the surface of the metal to be protected, as an additional protection, since it would greatly increase the efficiency of any anticorrosive method, reducing the electrochemical attack that generates corrosion