SSCC of welded joint for X80 pipeline steel and numerical simulation

Sulfide hydrogen stress corrosion cracking (SSCC) is the main factor to restrain the application of the pipeline steels. The critical stress intensity factor K_ISCC and crack propagation rate d a d t of base metal, weld and heat affected zone were obtained by the Wedge-open loading constant displacement specimens, based on the H₂S stress corrosion test for X80 pipeline steel.The factors affecting the performance of SSCC were analyzed through the microstructure, fracture pattern and hardness testing of the joints of X80 pipeline steel.By the analysis of the three-dimensional elastic-plastic finite element model of WOL sample, the stress field and hydrogen concentration distribution property of the crack tip were obtained.The heat affected zone showed minimum K_ISCC, maximum crack propagation rate and poor property of resisting stress corrosion cracking.The result of stress corrosion testing and the result of finite element numerical analysis verified each other.