A Method Of Stress Relieving For Hot Forging Dies For Use In Repairing Cracked Dies

摘要

The invention relates to stress relieving during weld repair process of the forging dies. The conventional thermal stress relief process used during die repairs is costly and time consuming. Further, large furnaces are required increasing the carbon footprint and maintenance. The invention uses pulsations for stress relieving. In the method of invention for repairing cracked die, the cracked die is treated by gouging out the area surrounding the crack and filling it with weld material. The treated die is pulsated for a pre-determined time, at a rate (Hz) at which the amplitude of pulsation is highest and hence, the cyclic stresses generated in the material are high. When these cyclic stresses are added to the residual stresses, the combined stress may lead to local yielding of the material, which reduces the overall stresses. Moreover, the pulsations increase the mobility of the dislocations, produced due to residual stresses. Increased mobility leads to rearrangement of dislocations, which in turn reduces the residual stresses. Reference Figure: Figure 2