Vibratory Stress Relieving Equipment

The majority of welded structures, castings, forgings and other fabricated of machined parts contained residual stress because of the different thermal gradient associated with the work piece. The existence of these residual stress is undoubtedly the cause of dimensional instability.
The equipment STREL-Q is a portable VSR equipment. A typical STREL-Q equipment consist of an electro mechanical vibration exciter unit, and electronic vibration controller with monitor, a chart recorder, the vibration sensor and rubber cushion and clamps.
The typical operation time can be maximum one hour for most jobs, irrespective of size, shape or weight of the job.

Theory of VSR technique
Stress relieving by any method is associated with micro plastic deformation of atoms. These is achieved by injecting additional energy.
In VSR technique the vibrations in the form of mechanical energy is injected into the work piece. This applied energy is super imposed on the existing residual stresses. Because of this the resultant stress energy crosses the yield boundary, and hence the material undergo micro plastic deformation effecting reduction of residual stress value.

Advantages
 · VSR causes no metallurgical changes, and does not reduce yield strength, tensile strength of fatigue life, as in the case of thermal stress relieving (TSR).
 · The equipment is portable and simple to operate. The material handling cost are drastically reduced by bringing the process to the work piece.
 · The operating cost are dramatically reduced as very little power and time are consumed as compared to TSR.
 · The VSR technique can be used on any size, shape or weight of work piece. No change in the equipment is needed.
 · No undesirable side effects, such as oxidation or scaling as in the case of TSR.
 · Design and developed under license from CMTI, recognised Government of India research organisation.