Improved Method Of Shot Peening Control Examines Variables In Production Process

Author:  Sanderson, A.M. and Slingsby, R.G.
Source:  Conf Proc: ICSP-1, (p.159-166)
Doc ID:  1981029
Year of Publication:  1981
Abstract:  
In commercial practice, helical coil springs, such as automobile valve springs, are shot peened in bulk, the accepted method of control being the inclusion of Almen testpieces. This type of test piece is not representative of the components and in some cases the test results have been proved to be misleading. A new concept of control testpiece was designed in the form of a helical coil of wire. By fatigue testing at resonant frequency, rapid results were obtained which could be used to establish a measure of shot-peening efficiency. The test coil can be of the same specification and may be subjected to the same low-temp. stress relieving treatments as the components it represents. The basic features of the test equipment are described and results of a large-scale experiment on steel valve spring wire which examines the effect of varying the operating conditions of a production shot-peening plant are presented. Descriptors: Spring steels-- Surface finishing; Shot peening; Fatigue tests; Springs (elastic); Quality control