Evaluation On Corrosion Resistance Of X-65 Pipeline Steel To Various Species Of Microbes

Microbiologically Influenced Corrosion (MIC) deteriorates one of the most commonly used carbon steel pipelines which is the API 5L X-65 grade resulting in pitting damage. There are various types of microorganisms involved in this corrosion process most notably Sulfate Reducing Bacteria (SRB) , Slime Producing Bacteria (SLYM) , Acid-Producing Bacteria (APB) , Sulphur Oxidizing Bacteria (SOB) , Iron Oxidizing Bacteria (IOB) . This study analyses the contribution of different types of microbes as an individual and consortium on the corrosion of X-65 steel pipeline in terms of corrosion rate measurement from the exposure to two types of bacteria mainly SRB and APB. The technique used to measure the corrosion rate is through the weight loss study and electrochemical test. In the Weight Loss (WL) study, samples are immersed over a period of 4 weeks in oxygen free nutrients and bacteria. The weight is recorded after 4 weeks. In electrochemical test, samples are set up and LPR (Linear Polarization Resistance) test are run for 4 weeks. The readings are recorded and the results obtained are compared between both the test methods to validate the results.