Abstract
The cracking susceptibility of two commercial API 5 L X80 steels was compared under acidic environment and electrochemical hydrogen charging. The microstructure and internal cracks of both steels were characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) to elucidate the main factors affecting crack resistance. In comparison, the steel with slightly higher strength and hardness showed much higher hydrogen induced cracking susceptibility. Moreover, cracks in the steel with low hydrogen susceptibility exhibited a predominantly transgranular propagation mode, while a mixed intergranular and transgranular mode in the steel with high hydrogen susceptibility. Long grain boundaries connected along the rolling direction and irregular M/A constituents distributed along the grain boundaries was the main factor causing the reduction of hydrogen-induced crack propagation resistance.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
