Effect of Cooling Rate on Properties and Microstructure during Solidification and Heat Treatment of Steels

Steel is an alloy of iron and carbon. The properties of the steel can be controlled by various means of altering the composition and/or by adding alloying elements or through heat treatment process. Steel is well known to its strength and ductility, combination of which contributes toughness. The property can also be altered by controlling the cooling rate of the liquid melt during solidification of various steel group materials. Solidification is a phase transformation process in which liquid is transformed into solid phase upon cooling by liberating the super heat and latent heat of fusion. The properties can be controlled by controlling the microstructure obtained after solidification in turn its properties. Microstructures are at the centre of materials science and engineering. They are the strategic link between materials processing and materials behavior. Microstructure control is therefore essential for any processing activity. One of the most important processing routes for many materials, especially metals and alloys is solidification. An attempt has been made to review various literatures from many researches related to cooling rate of the liquid metal during solidification, many heat treatment processes and its effect on micro structural changes, mechanical and tribological characteristics.