The shot peening process becomes increasingly important for all parts that are exposed to high alternating stresses, such as clutch springs, leaf or coil springs and gear components. By shot peening these parts their lifetime and therefore replacement cycle can be increased!
What is Shot Peening?
Compressive residual stress is generated into the surface layer of the parts under very controlled conditions. This compressive residual stress is beneficial in the prevention of crack formation and propagation. To obtain the best possible peening results it is of great importance to ensure the following:
Abrasive used remains the exact same size and shape
Constant velocity of the abrasive
Complete exposure of the part surface to the abrasive
How are Shot Peening results measured?
As an industry standard the Shot Peening results are usually measured by the following two parameters:
- Peening Intensity (Almen Value) Almen Strips (available in different thicknesses) are peened while mounted on a holding fixture. Once the peening process is completed the Almen Strips are removed and the height of the arc that was generated is measured, giving the so called Arc Height or Almen Value.
- Coverage Rate A visual inspection on the part itself to check the number of dimples/dents generated during the peening process. Measured in “percentages of coverage”, this is usually between 80% to 200% of coverage
Vibratory Sieves and MagnaValves for best peening consistency
Coil spring machines for peening of individual springs or batch processing