Please choose your delivery country and your customer group
The microstructural parameters contributing to the strength and toughness of low carbon, microalloyed, precipitation hardenable steels were identified in two ASTM A710, grade A, 50 mm thick plates in the reaustenitized, quenched and aged condition. Tensile, impact toughness and fracture toughness properties were determined over a full range of test temperatures to characterize the mechanical behavior and the fracture processes in the fracture mode transition temperature region, especially as related to cleavage failure and cracking parallel to the loading direction (longitudinal cracking). Microstructural and fractographic characterization, carbide precipitates (in the longitudinal direction) and a non-homogeneous grain size distribution as the primary contributing factors to lower toughness, while copper precipitation played a large role in strengthening. Keywords: HSLA steel, Structure/property relationship, Fracture characteristics, Physical metallurgy. (KT)