- Accueil
- Volume 13 (1994)
- Number 2 - Proceedings of the sixth European congr...
- Effect of quenching temperature on microstructure and properties of cast duplex stainless steel
Visualisation(s): 837 (0 ULiège)
Téléchargement(s): 54 (0 ULiège)
Effect of quenching temperature on microstructure and properties of cast duplex stainless steel
Abstract
This paper considers the influence of microstructural changes obtained by suitable heat treatment on impact toughness and pitting corrosion resistance of cast duplex stainless steel 0.08C-22.5Cr-8Ni-2Mo-3.5Cu. Investigated steel was annealed in the temperature range from 1000 to 1300 °C for lh and water quenched. Microstructure of specimens obtained from broken Charpy bars was characterized quantitatively using a semi-automatic image analyser. The stereological parameters: Vv, SV and Sv/VV were estimated by a linear method. The localized corrosion behavior was studied in 0.5M NaCl using the potentiodynamic anodig polarisation method. The changes in microstructure are pronounced from I100 C. In comparison with the cast structure ferrite/austenite ratio gradually increases while the surface density and specific (surface decrease. The impact toughness, however, reaches a maximum at H00 C and then decreases. The corrosion resistance of all heat treated alloys is improved. The lowest current density and best resistancce to pit initiation are achieved by annealing in the range from 1100 to 1210 °C. The results indicate that the ferrite/austenite ratio itself is a very important but not a single factor determining the mechanical and corrosion properties of cast duplex steel.