Sensitivity of the J-Integral Method for Estimating the Hydrogen Embrittlement of Ferritic-Pearlitic Pipe Steel

The paper is devoted to analyzing the sensitivity of pipe steel’s several crack growth resistance characteristics to electrochemical hydrogen pre-charging of different intensities using the J-integral method. Beam specimens with edge cracks were tested by three-point bending loading. In addition to the fracture toughness, which corresponded to the static crack growth increment ∆a = 0.2 mm, other crack growth resistance characteristics were used: the level of J for crack initiation and the slope of the J-∆a plot. The significant effect of specimen orientation relative to the rolling direction on the fracture toughness of specimens both without hydrogen charging and after hydrogen charging was shown. It was found that the slope of the J-∆a plot most sensitively characterizes the hydrogen embrittlement of steel.