Outokumpu Investigates Microbiologically Influenced Corrosion on Stainless Steel in Wastewater Treatment Plants
Outokumpu Oyj has released a publication focusing on Microbiologically Influenced Corrosion (MIC) on stainless steels. The research examines material performance in the challenging environments of wastewater treatment facilities.
Steel company Outokumpu Oyj has published research findings on the performance of stainless steels in wastewater treatment plant conditions. This publication in their ACOM magazine delves into the specifics of Microbiologically Influenced Corrosion (MIC).
The article details field tests conducted across six wastewater treatment plants. Welded coupons were exposed in the final settling tanks. At two facilities, an ennoblement of the open circuit potential, similar to observations in seawater, was recorded. Pitting corrosion was noted under deposits on AISI 304 and AISI 316 grades in one plant.
In contrast, the stainless steel grade 2205 (UNS S31803) showed no corrosion after the field tests. Laboratory measurements were also performed to assess the risk of MIC in the final aerobic stages of wastewater treatment systems. The findings from these lab tests aligned well with the field observations, contributing to a risk assessment model for MIC in these environments.
The publication highlights the role of stainless steel as a construction material in wastewater treatment plants, while emphasizing the critical need for correct material selection based on specific process stages and influent composition. The magazine also featured service experience with high-performance stainless steels in aggressive freshwater environments.