| 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) |
|
|
| Key Words |
| Duplex stainless steel, Superplasticity, χ phase, Internal variable theory, Dynamic recrystallization Grain/phase boundary sliding |
|
|
 |
|
