材料期刊网

Two parameters, surface yield strength and surface work hardening exponent, have been newly suggested in this paper to characterize the superficial mechanical features in engineering metallic materials. Emphasis was placed on the method by which the two parameters are determined. X-ray stress determination and strain gage techniques were employed to measure stress and strain. The Mises effective stresses at a sample surface under different loading conditions were then calculated with the measured data; hence, the relationship between stress and strain was available. Consequently, with the data processing procedure for general yield point and work hardening exponent of uniaxially loaded materials, the yield point and work hardening exponent at the sample surface can thereby be obtained. Experimental studies on a shot-peened surface showed satisfactory results when the described method was used.