| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1699691 | Procedia CIRP | 2015 | 6 Pages |
Austenitic stainless steels are generally difficult to machine when compared to carbon or low alloy steels. The presence of Cr, Ni, and Mo raises the temperature in the flow zone during machining. These steels are strongly work hardening, and usually bond to the tool forming a build-up-edge. The increase of the tool life and better removal rates can be achieved through the use of free cutting austenitic stainless steels. In these steels, sulfide and manganese can be added to form sulfide inclusions (MnS) that can induce stress concentration in the deforming material and facilitate the chip fracture. Finite element method simulation of the machining was carried out to investigate the influence of the inclusions in the machinability of the austenitic stainless steel. The simulation considers that the microstructure of the steel has two main constituents; the matrix of austenitic stainless steel and inclusions. Two simulation groups were carried out, the first one analyzing the machining cutting process of the workpiece and tool, and the second one was performed in a small area corresponding to a region inside the primary shear zone, where the stress concentrator effect of the inclusions in the austenitic stainless steel matrix was analyzed. This procedure was repeated for microstructures with different inclusions size, volume fraction and morphologies. The results obtained for the stress concentrations and strain near the inclusions showed that inclusions with elongated shapes usually give higher stresses than circular ones. Additionally,it was found that increasing the size of inclusions also resulted in higher stresses.
