Abstract
The fracture mode of austenitic steel may feature a ductile to brittle transition (DBT), depending on alloy composition and temperature. The DBT variation can be explained in terms of the actual deformation structure evolving during cold work and the correlated internal stresses. The crucial features of microstructure causing brittle fracture are found to be the intersections of deformation twins and the total density of free dislocations. To avoid brittle fracture, the stresses of intersecting twins must be screened by dislocations. Manganese and nitrogen promote brittle fracture since they lower the stacking fault energy and thus shift the onset of twinning to low strain levels where the total dislocation density is low. Nickel additions oppose this trend. The results of the microstructural fracture model agree well with experimental results and the model is confirmed by continuum-mechanical considerations.
| Original language | English |
|---|---|
| Pages (from-to) | 2211-2217 |
| Number of pages | 7 |
| Journal | Acta Metallurgica Et Materialia |
| Volume | 42 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1994 |