Comparison and Difference

What is the difference between shot peening and shot blasting?

 

What is Shot peening ?

Shot peening is a cold working process used to produce a compressive residual stress layer and modify mechanical properties of metals and composites. It entails impacting a surface with shot (round metallic, glass, or ceramic particles) with force sufficient to create plastic deformation.

In machining, shot peening is used to strengthen and relieve stress in components like steel automobile crankshafts and connecting rods. In architecture it provides a muted finish to metal.

Shot peening is similar to sandblasting, except that it operates by the mechanism ofplasticity rather than abrasion: each particle functions as a ball-peen hammer. In practice, this means that less material is removed by the process, and less dust created.

 

What is Shot Blasting ?

Shot Blasting is a surface finishing technique that involves rapidly impacting the surface of an object with a controlled stream of abrasive shot material. It is faster and more effective than filing for removing flash that my remain on a part after the casting or stamping process.

Shot Blasting is also used for removing burrs, scale and rust that may interfere with the part's integrity, appearance or definition. Shot blasting can also prepare the surface of a part for coating by removing surface contaminants and provide a surface profile for increased coating adhesion.

Shot Blasting is different than Shot Peening which is used to induce compressive stresses on a part's surface for increased fatigue life, increasing the part strength or preventing fretting.

 

  Shot Blasting Shot Peening
Definition Shot blasting or blast cleaning is a process in which an abrasive material is accelerated through a pressurized nozzle or centrifugal wheel and directed at the surface of a part to clean or otherwise prepare the part surface for further treatment. Shot peening is a cold working process, which uses the mass and velocity of a shot stream to produce residual compressive stress at the surface of the part.
It is a precisely controlled process relying on careful selection and control of media,intensity, coverage and equipment.
At the time of shot impact, the metal surface yields in tension due to localized stretching that occurs,while the near surface layer is left in a residual compressive state due to the material’s attemptto restore the surface to its original shape
Media used Blasting media includes sand; steel shot; cut wire shot; chilled iron; garnet,
a sharp hard abrasive glass beads used to polish rather than remove surface coatings on soft metals
and plastics.
,intensity, coverage and equipment.
At the time of shot impact, the metal surface yields in tension due to localized stretching that occurs,while the near surface layer is left in a residual compressive state due to the material’s attemptto restore the surface to its original shape
Peening media must remain predominately round and uniform in diameter to avoid
surface damage upon impact and to maintain a uniform compressive stress layer.
> ,intensity, coverage and equipment.
At the time of shot impact, the metal surface yields in tension due to localized stretching that occurs,while the near surface layer is left in a residual compressive state due to the material’s attemptto restore the surface to its original shape
Applications Shot blasting can be used on castings, forgings, and stampings to produce auniform surface texture and for descaling, deburring, and deflashing.
Shot blasting is used in a wide variety of industries including automotive, marine, mining, and
medical applications.
he metal surface yields in tension due to localized stretching that occurs,while the near surface layer is left in a residual compressive state due to the material’s attemptto restore the surface to its original shape
A variety of different metallic based materials are currently shot peened including: high
strength steels,carburized and decarburized steels, cast and austempered ductile iron, and
nonferrous alloys of aluminum, titanium and magnesium.Powder metal parts also benefit from
shot peening.
connecting rods, crankshafts, compression springs, torsion and anti-sway bars and metal implants.
essive state due to the material’s attemptto restore the surface to its original shape