Distribution of hydrogen in the zone of a fatigue crack and relationships governing its propagation in electrolytically hydrogen charged 07Kh16N6 steel

The effect of electrolytic H on the static and cyclic cracking resistance of 07Kh16N6 steel with a martensitic structure containing < 10% retained austenite was studied. A curve of H distribution in the thickness of a specimen was constructed. Variation of H concentration at the crack tip was observed and was used to postulate a H embrittlement theory for fatigue crack growth. The theory can be used to calculate the endurance of components and structural members with crack-like defects in penetration of H into steel from corrosion-active media or as a result of processing operations.