Effect of microstructures on deformation behaviour of high-strength low-alloy steel

The role played by microstructural constituents of high-strength low-alloy (HSLA) steel in controlling the deformation processes has been studied. The steel was solution treated and water quenched followed by ageing at various temperatures. Microstructural characterization has been carried out by using scanning electron microscope and transmission electron microscope. Tensile tests were conducted as per ASTM standard at constant displacement rate. The conditions under which microvoid coalescence was suspended in spite of a constant resident population of void initiating carbide and carbo-nitride particles have been explained. The major role played by the coherency of Cu precipitates in controlling dislocations movement; and hence, plastic flow is thought to be responsible for the effects observed.