Study on corrosive-fatigue crack growth in steels of higher strength

The paper presents results of a study on a corrosive-fatigue crack growth across material and development of a semi-elliptical surface crack in weldable steels of higher strength and of a ferrite-perlitic structure 15G2ANb and 18G2AV-special. The tests were performed in two environments: in air and in 3.5% NaCl water solution. Changing tensile loadings at a constant amplitude and at cycle asymmetry coefficient R=0.2 were applied. The results showed a significant influence of the corrosive environment on a crack growth across material. Test performed on the samples with semi-elliptical crack confirmed the influence of the corrosive environment as well as of the loading frequencies and sample widths on the length development of the cracks on the sample surface.