Cautionary Tale: Shot Peen Stress Relief

Author:  Mark Hayes, Institute of Spring Technology
Source:  The Shot Peener magazine, Vol 29, Issue 1, Winter 2015
Doc ID:  2015011
Year of Publication:  2015
Abstract:  
The Manager of a spring manufacturing company recently asked why his company always gave compression springs a stress relief heat treatment after shot peening, except when the springs are warm prestressed or painted after peening. Once the effect of this process had been explained, and confirmation had been given that the heating for warm prestressing or paint curing (at 180-200°C) did the same job as the stress relief, the manager then wanted a technical explanation of exactly how the stress relief worked.