Localized Corrosion Resistance Assessment of 11 Alloys in the Presence of DBNPA Biocide: A Material Compatibility Study

Abstract

Microbiologically influenced corrosion is a common problem in the oil and gas industry. It is a type of corrosion induced by biofilm-forming microorganisms such as sulfate-reducing bacteria which produces corrosive compounds as a product of their respiration. The most indicated treatment for the issue is the use of biocides, chemical substances used to kill microbes. However, biocides are corrosive to many materials, making their selection a problem. The 2,2-dibromopropanediamide (BDNPA) is a biocide used to control the growth of a wide range microorganisms. There is a literature gap for selecting materials that can be used with DBNPA Biocide without risk of corrosion. Hence, this research is dedicated to investigating the corrosion behaviour of commonly used alloys in a DBNPA solution. This work evaluated 11 alloys commonly used in the laboratory for the manufacture of instrumentation piping. Anodic polarization tests and 30 days immersion tests were carried out in a 100% DBNPA solution at two temperatures (25 and 40 ºC). Among the analysed alloys, only 4 were approved by the tests in all tested temperature ranges (Titanium Grade 2, Hastelloy C276, Inconel 625 and Superduplex Steel SAF 2507). These alloys did not present a localized corrosion process in any of the 30-day immersion tests, in addition, they obtained a significant passivation domain in the anodic polarization test at 40 ºC. The remaining alloys (AISI 304, AISI 316, AISI 317, AISI 321, AISI 347, Monel 400) were not approved in all temperature ranges tested for transport and storage of 100% BDNPA biocide solution.

Keywords

• Localized corrosion
• Biocides
• DBNPA