This study aims to evaluate the influence of heat input and dilution on the corrosion behaviour of a weld overlay coating of Inconel 625 deposited using a plasma transferred arc process. Cyclic potentiodynamic polarisation, double-loop electrochemical potentiometric reactivation and critical pitting temperature (CPT) experiments were performed to determine sensitisation and pitting corrosion resistance of the coating, besides microstructural characterisation and microhardness testing. The overlay showed to be resistant to sensitisation in all cases. Within the scope of this study, only the CPT test was able to cause pitting in the alloy, which showed that increments of the specimen's chemical dilution and heat input induced a lower CPT. This is mainly due to different chemical compositions among the distinct phases present in the coating.
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