Frequently Asked Questions

1. What is Stress?

For metallurgical purpose the stress can be defined as the force experienced between any parts of the body of continuous material. Normally they are in a state of equilibrium and balanced internally.

2. What is Residual Stress?

The Stresses in the body, which are not in the state of equilibrium and are not balanced internally, is known as the Residual Stress.

3. What is the effect of Residual Stress?

Residual Stress is the main cause of dimensional instability of the component. Hence they cause the premature failure of the component if not relieved or redistributed for equilibrium.

4. How the stress level is evaluated & weather we can know that the stresses have been relieved?

Unfortunately there is no non-destructive technique available to indicate the Stress level. However, X ray defraction is the latest technique by which the effectiveness of the VSR is evaluated at CMTI, but again it is the destructive and the laboratory method. In Heat Treatment also no test is applied for the efficacy, and the procedure is blindly applied.

5. How Reliable and effective VSR is?

VSR is equally reliable as TSR for achieving the dimensional stability of the metal. It has been tested and proved at CMTI, a Govt. recognized research institute, India. However it is not the direct replacement to thermal treatment for annealing, hardening or any other treatment where metallurgical changes are required in the metal.

6. Weather this process is approved under any code or standard?

In India CMTI, National Physical Laboratory and other institutions recognize the process. Many large organizations have also accepted and use the VSR technique. The Republic of China has standardised the code for “ The selection of the technical perameters and requirements for vibrating stress relief process.”
The code is JB/T5926-91.

7. How big jobs can be stress relieved by this process?

This method does not have any limitation by size, shape or weight of the Job. Large or heavy jobs are no problem but small jobs may need certain fixtures to be prepared to carry out the process.

8. What should be the frequency and the duration of the vibration?

Every component has its own natural frequency. To maximize the effect, the job should be vibrated to its natural frequency and its harmonics. The typical duration can be 10 minutes at a given frequency. Most jobs get stabilized when treated for 15 minutes each at two different harmonic frequencies.

9. What should be the frequency and the duration of the vibration?

Every component has its own natural frequency. To maximize the effect, the job should be vibrated to its natural frequency and its harmonics. The typical duration can be 10 minutes at a given frequency. Most jobs get stabilized when treated for 15 minutes each at two different harmonic frequencies.

10. Weather the job can be treated at site?

The VSR equipment is a portable machine and can be easily carried to the site. The job is to be isolated from the ground and then the process is applied at the site itself. Also almost all metals can be treated by VSR method except the precipitation hardenable materials and severely cold-formed materials. We carry out the job at your site for VSR treatment provided the quantum permits.