A Fracture Strain Based Numerical Prediction Method For Hydrogen Effect on Fracture Toughness(star)

In this paper, a finite element (FE) simulation method based on the multi-axial fracture strain model is proposed to predict the effect of hydrogen embrittlement on fracture toughness and is applied to test data on conventionally forged (CF) 21-6-9 stainless steel. For the uncharged material, the damage model parameters are determined from the tensile and fracture toughness test results. A hydrogen-embrittlement constant is introduced to modify the multi-axial fracture strain for hydrogen-charged materials. The predicted fracture toughness results using the modified multi-axial fracture strain agree closely with the experimental data of CF 21-6-9 stainless steel precharged at two different hydrogen concentrations, 78 and 210 wppm.