The Effect of Desulfovibrio Desulfuricans To Carbon Steel Grade API 5L X70

Abstract

Microbiologically Influenced Corrosion (MIC) caused by the presence of Sulfate-reducing bacteria (SRB) is a big concern in heavy industries. Pipeline infrastructure may experience severe metal loss due to corrosion induced by the species and can potentially lead to catastrophic failure. By studying SRB growth condition, important parameter can be controlled to prevent or slow down a corrosion process. This study discussed on the effect of pH value to the corrosion growth rate on API 5L X70 low carbon steel subjected to outer part of underground pipeline. In this research, the type of SRB that's been used is Postgate C of Desulfovibrio Desulfuricans. There are 80 numbers of samples prepared with various pH value and temperature, which each of the samples contains two coupon steel immersed in the medium together with SRB for 7, 14, 21 and 28 days. The process in determining weight loss is analyzed and the corrosion rate for each steel sample is identified by weight loss. The result is plotted and analyzed, the particular pH values and temperature affect the growth of SRB in the medium where the existence of SRB could accelerate the corrosion rate towards the steel surface of API X-70. The samples are exposed to SRB in days’ time. This experiment aims to determine the optimum temperature for SRB growth and demonstrate the corrosion rate simulation using One-Factor-at-A-Time method (OFAT) method. The consequences of SRB activity, it is shown that pitting corrosion produced on the surface of steel. In fact, the sulphur element is identified as one of the corrosion products due to SRB activity.