| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Coatings and Surface Engineering for Environmental Protection III
|
| Presentation Title |
Using Mechanical and Ion Polishing to Identify Structural and Chemical Defects for the Pitting Corrosion of a Compositionally Complex Steel |
| Author(s) |
Mark A. Wischhusen, Carol Glover, John Scully, Sean Agnew |
| On-Site Speaker (Planned) |
Mark A. Wischhusen |
| Abstract Scope |
Aqueous corrosion experiments have been performed on a compositionally complex steel with hierarchical microstructure involving coherent Heusler phase (L21) and B2 structured precipitates within a ferritic matrix. The pitting potential of the alloys (denoted FBB8 + Ti) is insensitive to Ti concentration, which ranged from 2 to 6 wt%, but is sensitive to the type of surface preparation. By varying surface preparation between a 0.05 micron colloidal silica and an Ar ion-polished finish, a change in the preferred site of corrosive attack was observed. Matrix attack, presumably at crystal defects, is the norm for mechanically polished samples, while pitting associated with Zr-rich particles occurs in the ion polished samples. A correlation between the passive current density and Ti concentration in the ion-polished samples, unseen with other surface preparations, was also uncovered. An explanation based upon solidification phenomena is proposed for the observed correlation. |
| Proceedings Inclusion? |
Planned: |