Stress-assisted oxidation behaviour of inconel 52M/316 austenitic stainless-steel dissimilar weld joints in a simulated pressurised water reactor

Abstract

The stress-assisted oxidation behaviour of Inconel 52 M/316 austenitic stainless-steel (SS) dissimilar weld joints (DMWJ) in a simulated pressurised water reactor environment was investigated. A corrosion galvanic couple formed between the Inconel 52 M and 316 SS due to differences in their nonferrous metal content. The electric field from the corrosion couple attracted metal cations (e.g. Fe2+, Cr3+) to the Inconel 52 M that were deposited as FeCr2O4. An additional corrosion galvanic couple was generated due to variations in the plastic deformation of the DMWJ. The superposition of electric fields from the different couples resulted in ridge-like oxide depositions in the fusion zone.

Keywords

• Dissimilar weld joints
• SEM
• TEM
• SKPFM
• Stress-assisted oxidation behaviour