EFFECT OF PLASTIC DEFORMATION PROPAGATION ON FATIGUE BEHAVIOUR OF METALS UNDER CYCLIC LOADING
金属材料在循环载荷下塑性变形传播对疲劳性能的影响

Studies of the fatigue crack initiation and propagation show that there is the loading frequency effect for the quenched and tempered or normalized 40Cr steel, but no the loading frequency effect for the solution treated ICr18Ni9Ti. The essential reason that causes the loading frequency effect is due to decrease in the plastic deformation propagation speed with the inereasing loading frequency. The decrease in plastic strain amplitude and the increase in residual compressive stress play a main role for the delaying fatigue crack initiation and the retarding crack propagation. The study of the loading frequency effect on the fatigue behaviour of the metals with the lower plastic deformation propagation speed possesses important engineering signification.