Low cycle fatigue life experiment of sheet metal with coldworking hole

In order to enhance the fatigue strength of the pressure equalizing hole on labyrinth seal disc for a compressor, three kinds of coldworking techniques with different processes were designed, namely, one-sided multiple extrusion process, cylindrical extrusion process and T shape extrusion process. Simulations on sheet metal with hole specimen for low cycle fatigue experimentation were designed using two kinds of materials (stainless steel 1Cr11Ni2W2MoV and high temperature nickel-alloy ZP742). Sheet metal with hole specimen was strengthened using two kinds of coldworking techniques, namely, single-side and repetitious extrusion method and T head extrusion method. And contrastive low cycle fatigue experimentation was done under two kinds of experiment temperatures, i.e. normal temperature and high temperature. The experimentation and analysis was made for different fatigue loads on how to influence the strength effect. The experiment results show that the effect of T head coldworking techniques is better for sheet metal filleted hole to improve low-cycle fatigue intension of the sheet metal with hole simulation specimen effectively. Under the same strength technique conditions, the size of low cycle fatigue load will influence the strength effect, and the smaller load means more obvious effect.