Abstract
The influence of environment on the degree of susceptibility of grain boundaries, and the effect of stress on the maximum intergranular stress corrosion crack length have been investigated in a Type 304 stainless steel. Fully sensitised specimens, exposed to acidified tetrathionate (K2S4O6) solutions, indicate a shift in the intergranular corrosion susceptibility criteria with the aggressiveness of the solution. Increasing fractions of the random grain boundary population showed immunity with a rise in pH. This behaviour may be attributed to grain boundary structure related chromium depletions, with different levels of chromium being attacked by different pH solutions. IGSCC tests of statically loaded Double-Beam-Bent specimens, exposed to tetrathionate solution, showed an effect of microstructure and stress on the maximum crack length. The results are compared with existing models for percolation-like behaviour and a new grain bridging model, which includes the effect of stress. The results support the grain bridging model and highlight the disadvantages of simplified models, which include only grain boundary statistics.
| Original language | English |
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| Title of host publication | 16th International Corrosion Congress |
| Place of Publication | Beijing |
| Publisher | Chinese Society for Corrosion and Protection |
| Publication status | Published - Sept 2005 |
| Event | 16th International Corrosion Congress - Beijing, China Duration: 19 Sept 2005 → 24 Sept 2005 |
Conference
| Conference | 16th International Corrosion Congress |
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| City | Beijing, China |
| Period | 19/09/05 → 24/09/05 |
Keywords
- Stainless Steel, Electron Backscatter Diffraction, Grain Boundary Susceptibility, Grain Bridging, Short Crack Length Predictions.