Abstract
Due to their diverse microstructures, micro-alloyed steels are increasingly being adopted across various industries. While extensive literature exists on the processing routes of these steels, experimental data on their suitability for fracture mechanics-based design and manufacturing approaches is relatively scarce, particularly in two areas: (1) the alteration of fundamental fracture mechanics properties of micro-alloyed steels in the presence of structural restraints such as pre-stress and pre-strain, and (2) a comparative study of the effect of heat treatment practices on the fracture mechanics properties of micro-alloyed steels relative to their as-rolled conditions. This study addresses these gaps by experimentally determining the quasi-static initiation fracture toughness (J1c) of low carbon (0.19%) micro-alloyed steel in its as-rolled condition, following ASTM E-1820 standards, without any heat treatment. Additionally, the study examines the effects of normalizing, shot-peening, and cyaniding followed by shot-peening on the fracture toughness parameter. The results indicate that normalizing, shot-peening, and cyaniding, followed by shot-peening, positively influence the initiation fracture toughness of this micro-alloyed steel.
