An investigation is performed into the grain boundary character distribution (GBCD), degree of sensitization (DOS), and intergranular corrosion (IGC) resistance of Alloy 82 overlay welds prepared using a manual gas tungsten arc welding (GTAW) process. Four different weldments are considered, namely as-welded (AW), sensitized (AW+SEN), solution-annealed (SS), and solution-annealed and then sensitized (SS+SEN). The results show that approximately 67.9% and 212.4 cm/cm2 of the grain boundaries in the weldments were prepared by GTAW process found AW specimens are high-angle boundaries (>15°). These boundaries prompt the precipitation of fine Cr-carbides during sensitization treatment, and therefore cause the formation of Cr-depletion zones close to the grain boundary. Consequently, the AW+SEN weldment has a high DOS. By contrast, AW+SEN welds are processed using a laser surface melting (LSM) technique with a continuous CO 2 laser beam and scanning speeds in the range of 0.8~1.2 m/min. It is shown that the LSM treatment could improve IGC and pitting corrosion resistance of the overlay weld mainly by reducing the amounts of fine precipitates along the subgrain boundaries of sensitized weld.
|Translated title of the contribution||Microstructure and Intergranular Corrosion Resistance Evaluation of Alloy 82 Weldments|
|Number of pages||13|
|Journal||Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao|
|Publication status||Published - 2018 Apr 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering