Shot Peening and Coverage

Author:  Tange, Okada
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002067
Year of Publication:  2002
Abstract:  
Authors A. Tange, H. Okada NHK Spring Co., Ltd., Yokohama, Japan Introduction As for the processing conditions of shot peening, there are the amount of shot, shot size, arc height, coverage, etc. However, when remarking to the coverage, no systematical study concerned with the relationship with the fatigue strength, can be seen. It would not be also certain that the over peening where fatigue strength will reduce if processing time is too long, exists 1). It can be said that it is not clear about whether the optimum conditions between the coverage and fatigue strength can be decided. However, it is difficult to specify the value of coverage because the measuring method of coverage is not designated. Therefore, it is difficult to discuss the relationship between the coverage and fatigue strength. In this paper, the following studies to specify the value of coverage were made: [1] experimentally obtain the relationship between the diameter of dent formed by shot peening, shot size, the shot movement energy (shot speed and shot weight) and the hardness of peened work, and express the experimental results to the formula by multiple regression analysis. [2] it was shown that the coverage can be simulated by the Monte Carlo method. [3] in order to study over peening phenomenon, the fatigue tests with the coverage of 36%, 98% and 1000%, were carried out. It was realized that there were no fatigue strength reduction with 1000% coverage.