| Title |
Internal Variable Approach to Superplastic Deformation of Duplex Stainless Steel |
| Authors |
박재신(Jae Sin Park); 방원규(Won Kyu Bang); 이형직(Hyong Jik Lee); 장영원(Young Won Chang) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Duplex stainless steel; Superplasticity; χ phase; Internal variable theory; Dynamic recrystallization Grain/phase boundary sliding |
| Abstract |
An internal variable theory has been used in this study to investigate quantitatively the major deformation mechanism of a duplex stainless steel. The flow curves obtained from load relaxation tests were found separable into two parts, viz. grain matrix deformation (GMD) curve and grain/phase boundary sliding (G/PBS) curve as was predicted by the internal variable theory. The major deformation mechanism of duplex stainless steel at high temperature is found to be a dynamic recrystallization (DRX) at an early stage of deformation, but grain/phase boundary sliding becomes the major deformation mechanism at the late stage of deformation. Additionally, x phase precipitated first by replacing Mo with W in duplex stainless steels appears to improve the superplastic deformation characteristics when it exists below a critical level. (Received May 19, 2004) |