Study of flow-assisted corrosion (FAC) in a API 5L X-70 steel in a brine-H2S-CO2 system using the rotating cylindrical electrode
Abstract
Corrosion caused by the mixture CO2/H2S in the transport of hydrocarbons is one of the most important research areas in the energy industry due to the severe problems it produces during the wear and tear of the pipes. Based in previous studies, in the present investigation the corrosion of API 5L X-70 steel in media with CO2 and H2S is studied as well as mixtures of both media, by means of a rotating cylindrical electrode due to the need to know the behavior of corrosion products in metals. The corrosion rate is evaluated at different pressures of H2S and CO2 and at 30 and 60 °C using the potentiodynamic polarization resistance measurements. From the results, it is observed that steel at the conditions of 0.8 bar H2S + 0.2 bar CO2 at 30 °C, yielded the lowest corrosion rate. This behavior is attributed to the fact that when H2S predominates it allows the formation of a greater number of protective layers comprised by a mixture of oxides, sulfides, sulfates and carbonates as corrosion products.
- Publication:
-
Materials Research Express
- Pub Date:
- June 2019
- DOI:
- 10.1088/2053-1591/ab08c7
- Bibcode:
- 2019MRE.....6f6550P
- Keywords:
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- Corrosion by CO2/H2S;
- corrosion products;
- API 5L X70 steel;
- polarization resistance