- Microalloy steels are potentially used for applications in earthmoving equipments and automobile components. Their excellent combination of strength and ductility/formability at lower costs are the distinct advantages over similar high strength low alloy steels. In the present investigation, fatigue behavior/fracture toughness of microalloy steel was studied to evaluate their influence on microstructure. It was found that the fatigue properties (in terms of fracture toughness) as well as the tensile properties (in terms of 0.2% proof stress) of microalloy steels increased with increase in martensite content. Artificial neural network (ANN) based theoretical prediction model was developed and was found to exhibit excellent matching with the experimental results. This simultaneous increase in fatigue and strength properties of microalloy steels makes them potential materials for various engineering applications.