Role of Microstructural Anisotropy in the Hydrogen-Assisted Fracture of Pearlitic Steel Notched Bars.

This paper analyzes the role of microstructural anisotropy generated by cold drawing in the hydrogen-assisted fracture of progressively drawn pearlitic steel notched bars. Very different notched geometries were used to generate quite distinct stress triaxiality distributions (and thus very different constraint levels) in the vicinity of the notch tip, and fracture surfaces were classified in accordance with three micromechanical models of hydrogen-assisted micro-damage on the basis of the micro-fracture maps assembled by scanning electron microscopy over the fractured area of the notched specimens. [ABSTRACT FROM AUTHOR]