Corrosion Failure Reason of 254SMO Super Austenitic Stainless Steel Heat Exchange Plate

The heat exchange plate (steel 254SMO) used in a wastewater treatment project at a certain coal chemical plant had undergone corrosion failure after about half a year of service. The wastewater quality of the factory was analyzed, and the heat exchange plate was subjected to macroscopic examination, composition analysis, metallographic analysis, scanning electron microscopy analysis, and energy spectrum analysis. The results show that the wastewater medium had a high salt content, a wide variety of pollutants, and a high medium temperature, forming a special corrosive environment. The sealing ring of the heat exchange plate would form a gap structure, which was caused by the medium environment and its own structure of the heat exchange plate. As the corrosion progresses, it ultimately led to the failure and leakage of the 254SMO super austenitic stainless steel heat exchange plate. It was recommended to strengthen the protection of the system by adding corrosion inhibitors and upgrading the material of the heat exchange plate.