Corrosion behavior of radial friction welded supermartensitic stainless steel pipes

• Supermartensitic stainless steel pipes were radial friction welded.
• Electrochemical measurements were taken of the weldment’s different regions.
• The corrosion behavior of the weldment regions was better than BM in acid media.
• The tempered structure of the BM exhibits substantial Cr depletion.
• A decrease in pitting resistance was attributed to δ-ferrite formation.

Supermartensitic stainless steel pipes were radial friction (RF) welded and their corrosion properties were determined based on electrochemical tests. Measurements were performed on samples taken from the base metal (BM), weld interface, and consumable ring (CR) of the RF weldment. The corrosion properties are discussed in terms of their resulting metallurgical microstructure. In acid media, RF weldment regions presented better corrosion performance than the tempered structure of the BM. The Cr carbide precipitation that occurs during tempering causes substantial depletion of Cr, while δ-ferrite formation during welding cycle decreases the pitting corrosion resistance of the material.

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