APPLICATIONS OF VIBRATORY STRESS RELIEVING
During Manufacture
- Before rough machining, milling or grinding operations.
- Before final machining, milling or grinding operations.
- Following various stages of fabrication.
- On completion of fabrication & welding.
- Following heat treatment or hardening.
- Following straightening operations/
- Following repairs and before reinserting into service.
- Periodically for preventative maintenance.
Types of Components
- Plate
- Bar
- Weldments
- Castings
- Forgings
- Extrusions
- Machined Components
- Fabrications (up to 200t)
- Composites
- Plastics (including pipe)
Benefits of VSR Include
• It can give equal stress reduction and stability to thermal stress relieving.
• If applied after rough machining or semi-finishing, accuracy is only limited by the accuracy of the finishing method.
• It can be used upon materials not treatable by thermal stress relieving.
• Time savings of approximately 50:1.
• VSR is brought to YOU, the component does not have to leave your works.
• Treatment capabilities of up to 200t.
• No distortion, loss of hardness or yield strength of materials.
Materials on which VSR can be used
• Low and medium carbon hot rolled steel.
• Low and medium carbon steel alloys.
• Tool steel alloys.
• High strength steel alloys.
• Cast irons including grey, nodular and mechanite.
• Aluminum and aluminum alloys.
• Stainless steels.
• Exotic metals including gold, titanium, inconel, and magnesium.
• Powdered metals including tungsten carbide and stellite.
Poor Applications for VSR
• Cold rolled steel.
• Burned edges.
• Copper and high copper content alloys.
• Materials where mechanical properties need to be altered.
• Severely cold worked steels.
VIBRATORY STRESS RELIEVING vs NO STRESS RELIEVING
It has been estimated that 50% of all the components that should be stress relieved are not.
Often the reason cited for skipping stress relieving is based upon the desire to avoid unwanted side effects associated with heat treatment.
Common unwanted side effects include:
• Distortion.
• Scaling.
• Change in material properties.
• Lengthy time restraints.
• Further reasons are time, cost and size limitations associated with furnace sizes.
Omitting stress relieving involves a risk
• The risk is in hoping that no problems will arise normally cracking, distortion, or a reduction in the component life cycle.
• A bigger, often forgotten risk, is any of the above will often generate dissatisfied customers.
• As VSR does not cause any of the mentioned unwanted side effects and the process is virtually limitless in size and weight capabilities not stress relieving is unnecessary.
Benefits of stress relieving (VSR) are many but briefly the common ones include:
• A reduction in distortion following machining (up to 93%).
• A reduction in machining time (up to 40%) by eliminating extra cuts or a lower cutting speed and rate due to distortion of the workpiece.
• Prevention of delayed distortion caused by a non stress relieved component undergoing an “ageing process” in service.
• A reduction in cracking, brought on by high residual stresses being reduced and a reduction in the “critical crack propagation rate”.
• Prevention of premature failure in service.
• Proven reductions in residual stress of up to 72%
• Redistribution of surface strains of 100%.
• Satisfied customers.