Velocity Characteristics of Shot Ball Corresponding to Impeller Blade Shape Based on Discrete Element Analysis

Author:  Jong Ho Myung, Taehyung Kim, Chan Gi Jung, Seung Ho Lee
Source:  ICSP-13
Doc ID:  2017095
Year of Publication:  2017
Abstract:  
Introduction: Shot peening is a technique that improves resistance characteristics from external fatigue loading by producing beneficial compressive residual stress on the metal surface [1]. Impeller-type shot peening equipment is widely used. Usually, plate blades have been used in impeller-type shot peening equipment due to their low cost. However, plate blades wear out frequently and need to be replaced at the same rate. In addition, frequent replacement and repair of damaged blades may cause increased maintenance costs. For this reason, a researcher theoretically calculated the shot velocity by designing the blade with a curved shape, and confirmed its effect [2]. However, in the equation, the shot velocity was calculated using only the velocity component corresponding to the impeller rotation. That is, physical properties such as the material, sizes of the shot ball and blade,and friction were not considered. For this reason, in this study, an improved blade shape was proposed to increase the shot velocity at the same impeller rotation, based on the discrete element (DE) analysis. The plate, curved, and plate-curved blades were adopted in the DE analyses. Additionally, the compressive residual stresses were investigated with respect to the physical characteristics in the single-shot impact finite element (FE) analysis model.