Microbiologically influenced corrosion (MIC) of steel – a study using correlative SEM, EDX and Raman microscopy

Microbiologically influenced corrosion (MIC) is responsible for 20% of all corrosion damage [1]. In thiscontext, there is great interest in understanding MIC especially, since it has been shown that some microbesslow down the rate of corrosion [2], while others speed it up [3]. During experiments in the Koralmtunnel,iron-oxidizing bacteria were found, to be part of a MIC causing, microbial community. The aim of theinvestigations is to observe the influence of MIC on steel on the macroscopic (corrosion rates CR, pittingcorrosion), and the microscopic side. A novel technique is applied for the latter, which combines Ramanimaging with scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDX) (ZeissSigma 300 VP; Oxford X-Max 80; WITec RISE). An example of a correlative SEM-EDX-Raman (RISE)measurement is shown in the figure.