| Title |
Effect of intermetallic precipitation on the properties of multi passed duplex stainless steel weldment |
| Authors |
(Seong Han Bae); (Hae Woo Lee) |
| DOI |
https://doi.org/10.3365/KJMM.2014.52.8.631 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
duplex stainless steel; welding; intermetallic compound; EBSD |
| Abstract |
Abstract: This study investigated the effect of the aging time of weldment of 24Cr-3.5Mo duplex stainless steel on the microstructure and corrosion behavior. After performing FCAW, we carried out heat treatments at varying times at 850 ℃ and performed observation of microstructure, potentio dynamic test, SEM-EDS analysis, and X-ray diffraction analysis. As the aging time increased, the fraction of δ-ferrite decreased sharply, but the fraction of γ slightly increased. The σ phase was generated at a non-metallic inclusion along the grain boundaries of δ-ferrite and γ, while the χ phase was generated in the structure of δ-ferrite. As the intermetallic compounds increased, the critical pitting potential fell sharply, and PREN of the surrounding structure decreased by 5 due to precipitation of the σ phase in 3.5% NaCl at 60 ℃. Pitting occurred intensively under a multi-pass line which relatively had more intermetallic compounds, and the precipitation of the σ phase caused the formation of Cr carbide. |