A New Approach to Characterization of Gas Turbine Components Affected by Pitting Corrosion

Among gas turbine components such as compressor blades made of precipitation-hardened martensitic stainless steel, a phenomenon known as pitting corrosion can occur on the surfaces of components during exposure to a marine environment. This can lead to surface degradation followed by crack initiation and further propagation with high-cycle fatigue as the main mode of damage. In order to obtain detailed statistical characterization of pitting severity, which may enable obtaining preventive models of the phenomena, a new study on pit size analysis and pitting inspection technique is proposed. In this investigation, pit depth values are considered as the main factor behind this type of failures. This article presents the results of pit depth assessment and other pitting characteristics with the use of confocal microscopy as a non-destructive technique. The results obtained show that confocal microscopy can be successfully used as a non-destructive tool for the evaluation of pitting severity.