A study on structure and properties of a hot forged HSLA-80 steel

In the present investigation a HSLA-80 grade steel was hot forged at various temperature ranges with varying amount of deformations and subsequently cooled in different cooling media like water, air and sand. Microstructure, mechanical properties and recrystallization behaviour of the steel were evaluated. In water quenched condition a critical amount of deformation is required to obtain the peak hardness and the amount of this critical deformation varies with forging temperature. At higher forging temperature beyond this critical deformation, recrystallization takes place, which reduces the hardness of the steel. On slow cooling from same finish forging temperature the hardness value increases due to precipitation effect. Higher strength and toughness in air-cooled steel is obtained due to the granular bainitic microstructure.