Abstract Scope |
A new heat treatment procedure has been investigated by considering AISI 4140 and AISI 4340 steels, which are widely used materials for cardan shafts. A multiphase in the microstructure of shafts has been detected by new technique. Additionally, the microstructure and mechanical properties of the materials obtained by the new heat treatment are determined. The production processes have been tried to be optimized for obtaining the shafts with longer fatigue life and less heat treatment defects.
Static and fatigue torsion tests have been carried by using MTS torsion fatigue test device with a static torque and dynamic torques capacities of 25,000 N-m and 11,600 N-m, respectively. Both load and torsion angle-controlled tests have been conducted. Results with the new heat treatment show that it is possible to obtain much more flawless structure and, therefore longer fatigue life which can be up to three times of an ordinary shaft life. |