Method for Shot-Peening and a Shot-Peening Machine

Author:  Yuji Kobayashi and Toshiya Tsuji
Source:  US Patent 9,073,176
Doc ID:  2015057
Year of Publication:  2015
Abstract:  
The cost for shot-peening is intended to be reduced. The method for shot-peening of the present invention comprises a first step for processing a work by shot-peening by projecting shots onto the work, and a second step for processing the work by shot-peening by projecting the shots onto the work at a speed for projecting the shots that is slower than the speed in the first step, wherein the second step uses the same shot-peening machine and same shots that have been used in the first step. By this method, an intended distribution of compressive residual stresses is obtained by the processes in the first and second steps and the surface roughness of the work is decreased by the process in the second step wherein the shots are projected at the speed that is slower than that in the first step. Further, no removal or supply of the shots and no re-setting of the conditions for the process that are related to the removal and supply of the shots are required. Multiple shot-peening machines do not need to be installed. Thus the cost for shot-peening is reduced.