Effect of complex loading during isothermal roll-forming on forming of hollow shafts out of hard-to-deform alloys

Fabrication of hollow shafts for gas turbine engines by traditional methods such as forging or pressing is characterized by high labor intensity and a low metal utilization ratio. Low technological effectiveness of these methods is caused by the low plasticity and workability of high-temperature alloys, of which the shafts are fabricated and their complex shapes as well. In the present work, the possibility of using isothermal roll-forming to enhance the efficiency of the manufacturing process of such parts is demonstrated. Computer and physics modeling of the shaft roll-forming process is carried out. The effect of complex loading of a billet and its configuration on strain localization and forming of an article during rollforming are demonstrated. The rational form of a billet is determined and method of its rollforming is developed that allows for forming a given article. The results of the study are used for quasiisothermal roll-forming of a real hollow shaft out of chromium steel EI962-Sh with given shape, a homogeneous structure and high level of mechanical properties.