Different processes involved in manufacturing like welding, casting, forging, machining, forming may introduce residual stress in the job. The stresses developed to developed in component may cause distortion in the job, which may result in . dimensional instability over a period of time. If the distortion is very severe, it may cause total destruction of the component.
Residual stresses can be relieved by many methods some of which were hammering the work piece with a wooden mallet and dropping a casting or weldment from a height to pile of sand. This may have created vibrations which caused the elimination of some of the residual stresses developed during manufacturing process. Ageing and annealing are the most recent methods. These earlier methods which were use for relieving stresses constituted the initial step towards the most effective and efficient method known as vibratory stress relief.
The vibratory stress relief process can be explained as a 'method of applying controlled low amplitude, low frequency vibrations in metal components to obtain dimensional stability and control for machining tolerances'. This method has now become the most accepted way of stress relieving as it is a cost-effective, rapid and suitable way of reducing stresses and finds its utility during process to achieve the dimensional stability.
