Controlled Shot Peening of Automotive Components

The controlled shot peening process is by no means new to the automotive industry. This process is routinely used on many mechanical components to increase fatigue life. In other cases, shot peening is used selectively to overcome unexpected service failures or to allow the use of existing designs in higher stress applications. Some of the more common applications of the shot peening process are engine valve springs, suspension springs, crankshafts, connecting rods, and various transmission components. Much data have been gathered on these and other components which indicate the significant increase in fatigue strength that can be realized as a result of this cold working process. Several examples of these improvements will be discussed, together with supporting S-N curves. Also discussed will be the use of new generation shot peening equipment employing microprocessor control and continuous monitoring of process variables to assure complete repeatability of the process. Improved inspection techniques will be included.