Abstract: The present invention provides a method for a shot-peening processing that can process in one step and thus reduce operating costs and the cost of equipment while increasing the efficiency of the treatment in the peening processing while achieving a peening effect similar to the effect obtained by shot-peening processing a plural number of times, that is, deeply generating compressive residual stress far from the top surface while generating the peak value of the compressive residual stress on the top surface. This method is characterized by projecting, on a product to be subjected to peening, shot in which two or three kinds of particles, each having a different predetermined average particle diameter and having a predetermined average particle diameter ratio to one another, are combined in a predetermined weight ratio.

Abstract: Disclosed is an apparatus for detecting at least one of an intensity and a density of shot blasting during shot treatment, which includes a shot bombardment and propagation member including a first part to be bombarded by a shot stream for generating elastic waves when bombarded by the shot stream and a second part for propagating the elastic waves therethrough, a transducer for receiving the elastic waves from the shot bombardment and propagation member and transducing the elastic waves into a high-frequency electrical signal, and a measuring circuit detecting at least one of the number of times of shot bombardment and the intensity of shot bombardment on the basis of the high-frequency electrical signal.