5-amino-1,3,4-thiadiazole-2-thiol corrosion current density and adsorption thermodynamics on astm a-890-1b stainless steel in a 3.5% nac1 solution

• M GUZMÁN ^[1] ; R LARA ^[1] ; L VERA ^[1]
  1. [1] Universidad Católica del Norte

     Universidad Católica del Norte

     Antofagasta, Chile

     
• Localización: Journal of the Chilean Chemical Society (Boletín de la Sociedad Chilena de Química), ISSN-e 0717-6309, ISSN 0366-1644, Vol. 54, Nº. 2, 2009, págs. 123-128
• Idioma: inglés
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• Resumen

  • Using the electrochemical linear polarization resistance technique, 5-amino-1,3,4-thiadiazole-2-thiol corrosion current density on ASTM A-890-1B steel is determined in a 3.5% NaC1 solution at different temperatures. The corrosion inhibition process is mixed. Apparent activation energy is calculated, being the one with inhibitor slightly greater than that without it. Adsorption matches Damaskin-Parsons isotherm, showing that molecules adsorbed by the metal surface reject each other. Three water molecules on the metal surface are replaced by one inhibitor molecule. This is demonstrated by calculating the surface these molecules project. Normal thermodynamic adsorption parameters are calculated, showing that the process is spontaneous and exothermic. Inhibitor adsorption on the metal surface is a chemical adsorption.