A computer model was developed to predict the life of cold drawn prestressing steel wires in ammonium thiocyanate. The model is formulated on the basis of hydrogen diffusion from the solution into the metal and a fracture criterion including both the stress level and a critical hydrogen concentration at the fracture point. It allows a detailed analysis of the influence of test variables such as stress level and temperature upon the hydrogen embrittlement susceptibility of the steel. Residual stresses generated at the wire surface during the cold drawing process can also be introduced into the model, thus demonstrating the important effect of the manufacturing procedure, which influences the hydrogen penetration by inducing surface residual stresses in the wire.
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