An Overview of Shot - Peening

Author:  A. Niku-Lari
Source:  Conf: (Bophal) Intl Conf on Shot Peening and Blast Cleaning (Book:Sharma/Ra
Doc ID:  1996002
Year of Publication:  1996
Abstract:  
Controlled shot-peening is an operation which is used largely in the manufacture of mechanical parts. It should not be confused with sand blasting used in cleaning or descaling parts. Shot peening is in fact a true machining operation which helps increase fatigue and stress corrosion resistance by creating beneficial residual surface stresses. The technique consists of propelling at high speed small beads of steel, cast iron, glass or cut wire against the part to be treated. The size of the beads can vary from 0.1 to 1.3 or even 2mm. The shot is blasted under conditions which must be totally controlled. The main advantage of this particular surface treatment is that is increases considerably the fatigue life of mechanical parts subjected to dynamic stresses. It has many uses in industry, particularly in the manufacture of parts as different as helical springs, rockers, welded joints, aircraft parts, transmission shafts, torsion bars, etc. At a time when the optimum characteristics are being demanded of mechanical assemblies, shot peening is a surface treatment method which is being increasingly chosen by engineers. However, shot peening technology is yet to be fully perfected and the substantial changes produced in the treated material make it difficult at the present time to put the best conditions into practical use.