Morphology of localized attack on the tension side of 3 1/2% Ni U-bend specimen in 0.5% acetic acid saturated with H₂2S at 0.1 MPa, balance N₂ (P_T = 1 atm). Magnification 200X.The depth of the pit before cracking was about 200 μm.

Dunlop, A. K. Stress corrosion cracking of low strength, low alloy nickel steels in sulfide environments. Corrosion 34, 88-96 (1978).