Abstract
The effects of the most important variables on continued growth and repassivation of open macroscopic corrosion pits in stainless steel sheets were investigated using two different artificial pit configurations. The pit growth was activated under anodic polarization either by injecting concentrated chloride solution into the pit or by initially filling the pit with chromic chloride crystals (CtC13.6H20). Experiments were made on sheet specimens of stainless steels of type UNS S31603 (316L) or UNS S312.54 in bulk solutions containing chloride and/or sulfate ions.
Various aspects of the test arrangements and pitting of stainless steels are discussed, including the electrolyte composition within the pits, repassivation potentials and the IR-drops associated with pit growth. It is demonstrated that using the artificial pit configurations the effects of the main variables affecting the conditions for growth and repassivation of open corrosion pits can be investigated quantitatively, including electrode potentials, temperature, and composition of the bulk solution. It is concluded that for continued growth of corrosion pits with large openings to the bulk solution, a strongly oxidizing environment is required, and that sulfate ions in amounts comparable to or in excess of that of chloride ions may stabilize pit growth.
Various aspects of the test arrangements and pitting of stainless steels are discussed, including the electrolyte composition within the pits, repassivation potentials and the IR-drops associated with pit growth. It is demonstrated that using the artificial pit configurations the effects of the main variables affecting the conditions for growth and repassivation of open corrosion pits can be investigated quantitatively, including electrode potentials, temperature, and composition of the bulk solution. It is concluded that for continued growth of corrosion pits with large openings to the bulk solution, a strongly oxidizing environment is required, and that sulfate ions in amounts comparable to or in excess of that of chloride ions may stabilize pit growth.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of Corrosion '98 |
| Subtitle of host publication | Corrosion in advanced materials and systems |
| Editors | Ron M. Latanision, John Scully |
| Place of Publication | Houston |
| Publisher | National Association of Corrosion Engineers (NACE) |
| Number of pages | 16 |
| ISBN (Print) | 978-1-57590-050-6 |
| Publication status | Published - 1998 |
| MoE publication type | A4 Article in a conference publication |
| Event | CORROSION 98 - San Diego, United States Duration: 21 Mar 1998 → 29 Mar 1998 |
Conference
| Conference | CORROSION 98 |
|---|---|
| Country/Territory | United States |
| City | San Diego |
| Period | 21/03/98 → 29/03/98 |