Correlation of strength and cyclic cracking resistance of steels with work-hardened structure

The results of strength and cyclic cracking resistance research of structural steels are given in the paper. Using methods of deformation and thermal treatment, structures with different dislocation build-ups were created. The increase of cold working degree caused an increase of strength and threshold cyclic cracking resistance of steels and a decrease of plasticity. The creation of a polygonized structure led to the decrease of strength properties and a threshold of cyclic cracking resistance at a simultaneous increase of plastic performance. The fatigue crack propagation curve of such a structure shifted to the area of higher crack growth rates. The cold working of the polygonized structure increased the number of structural defects and perfected the strength and cyclic cracking resistance performance. The change of the threshold cyclic cracking resistance curve coincided with the general course of the strength curve and was in the opposite relation with the curve of plasticity