Experimental investigation of shot peening: correlation of pressure and shot velocity to Almen intensity

Shot peening is a mechanical surface enhancement process that is extensively used in various industries to increase fatigue life of components. This process relies heavily on post-processing quantification such as Almen strip system. With the main objective of replacing the Almen strip system with suitable sensors, this study is performed with the intent of achieving real-time monitoring for the process and finding an alternative means to quantify it by correlating sensor signals to Almen intensity. The pressure drop across a typical shot peening nozzle using pressure sensors and its correlation to shot velocities using a high-speed camera and a ShotMeter™ obtained at different operating conditions was evaluated. The information from the pressure sensors and shot velocity was analyzed to ascertain the presence of any correlation with process inputs (pressure and mass flow rate) and process output (Almen intensity). By deploying pressure sensors at the inlet of the system and the nozzle, the study demonstrates the capability for a real-time monitoring and control of the shot peening process without using Almen strip system.