The steel tubes used in the Oil Industry are constantly exposed to hydrogen sulphide (H2S) which leads to the diffusion of hydrogen into the steel, provoking hydrogen induced embrittlement cracks and/or stress corrosion cracking. Welded joints, generally considered to be the critical region in pipelines, were evaluated in this study, using slow strain rate tensile testing (SSRT) and NACE TMO177/96 - Method A (standard tensile test) norm, verifying the behaviour of joints in API X-70 and X-80 grade steels, with regard to hydrogen embrittlement and stress corrosion cracking. Sodium thiosulphate was used in the slow strain rate tests permit the evaluation of hydrogen embrittlement and stress corrosion cracking while reducing testing costs and maintaining safety standards. The results show that the API X-70 and X-80 grade steels are susceptible to hydrogen embrittlement and stress corrosion cracking.