Effect of microstructure, phase formation on the mechanical and surface characteristics of low alloy medium carbon forged steels – A review

Forged steels are most commonly used in automobile industries because of their high toughness and ability to handle the impact. By controlling the heating temperature, cooling rates, and intensity of deformation, it is possible to have different microconstituents like pearlite, bainite, and a mixture of these phases. The type of microstructure obtained by forging has a positive effect in tailoring the property as per the product requirements. They have better surface properties compared to their counterpart cast iron. In this paper, an attempt is made to study the various properties of forged steels and the effect of cooling rates and alloying elements on the microstructure and hardness of the forged steel. The influence of laser hardening on the wear behavior of the forged steel is also reported. The effect of Titanium and Vanadium on the hardness of forged steel is considered and also the effect of the addition of Chromium on bainite steels is evaluated. The wear debris deposition in hot rolling to vintage glaze (Oxide Island) and interaction effect with high temperature oxidation hence, on tribology, is not elucidated yet. As surface tribology, laser hardening imparted an ultra-high level of skin hardness to forged steel which suppressed wear of adhesion and also reduced debris through abrasion. Finally, on the intense literature study, research gaps are recognized and presented.