Article ID Journal Published Year Pages File Type
1469364 Corrosion Science 2013 12 Pages PDF
Abstract

Type 347 stainless steel was solution annealed at three different temperatures (1100, 1250 and 1300 °C) followed by ageing at 650 and 750 °C. This was done to study the phase transformations that may occur in stainless steel 347 during welding and/or subsequent ageing. The microstructural examination showed chromium carbide and σ phase formation at the grain boundaries after ageing. The electrochemical behaviour was evaluated by double-loop electrochemical potentiokinetic reactivation test and anodic polarisation in HCl solution. Chromium carbide precipitation caused large increase in the degree of sensitisation, while σ phase had the major effect in decreasing the pitting resistance.

► Electrochemical behaviour correlated with different phases in stainless steel 347. ► Formation of both Cr23C6 carbide and σ phase at the grain boundaries at 650 °C. ► Only σ phase formation at the grain boundaries at 750 °C. ► As opposed to σ phase, large Cr depletion due to carbide formation. ► Large decrease in pitting resistance due to σ phase as opposed to carbide formation.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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