Hydrogen Permeation and Hydrogen Induced Cracking of Drill Pipe Steel S135

Hydrogen permeation coefficient and diffusible hydrogen content in drill pipe steel S135 during cathodic charging with hydrogen were studied by an electrochemical method,and the hydrogen induced cracking (HIC) threshold stress of the steel was investigated using constant load tests.Experimental results showed that during dynamical charging of drill pipe steel S135 with hydrogen in 0.5 mol/ L H2SO4+0.25 g/L As2O3 solution,the concentration of diffusible hydrogen C0 was directly proportional to cathodic current density i.The threshold stress σHIC decreased linearly with increasing logarithm of hydrogen concentration lnC0 in constant load tests.