This paper describes a technique that can be used for the prevention of chevron cracks (or central burst defects) during the cold forward extrusion process with spherical dies. To characterize the behavior of the material and predict the formation of chevron cracks, it is necessary to determine the flow stress and critical damage value (CDV) of the billet material. The flow stress is obtained by homogeneous compression tests. Critical damage value (CDV) is determined from FEM simulations correlated with non-homogeneous compression tests and notched tensile tests. Two different materials are evaluated: SAE 1137 (hot rolled) and SAE 1524 (spheroidized).
| Number of Pages : | 6 |
| Published : | 11/01/2000 |
