Shot Peening and Grit Blasting - Effects on Surface Integrity-

Author:  Tosha, Lu, Guelorget, Nagashima
Source:  Conf Proc: ICSP-9 (pg 400-405)
Doc ID:  2005116
Year of Publication:  2005
Abstract:  
ABSTRACT This paper describes influence of factors such as particle size (0.55-2.2 mm), particle velocity (15-35 m/s) and work hardness on surface integrity. Hardness, residual stress and crystal transformation of areas affected by shot peening or grit blasting are examined. In order to clarify the influences of those factors on the surface integrity, a medium carbon steel (C:0.45%, 180HV) and an austenitic stainless steel (SUS304, 210HV) were peened by a centrifugal type peening machine using cast steel particles (650-800HV). The following results were obtained: (1) Shot peening maximum hardness is lower while depth of work-hardened layer is thicker. (2) Compressive residual stresses on the peened surface are larger than that of grit blasting. (3) Critical thickness of shot peening is about 50% thicker than that of grit blasting. (4) Strain-induced transformation happens with shot peening and grit blasting.