Microstructural Aspects of Premature Pitting Corrosion of Steel Pipe–Case Study

Abstract A premature pitting corrosion in seam-welded 3-inch L235 steel pipe was reported to occur after 8 years service. This part of a closed ice water cooling system, where the inlet temperature 6 °C and outlet 11 °C. The present work aimed investigate causes this through metallographic investigations. comprised visual examination internal surfaces microstructural examinations perforation regions (pitting areas) using optical scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. investigations showed that pits occurred only areas huge number specific micro-voids can be associated excessive presence trapped hydrogen dissolved steel, probably during steelmaking operations.