Fracture Behaviour of Copper Strengthened HSLA Steel

Abstract

High strength, high toughness and good weldability are the major criteria for engineering structural materials. HSLA-100 steel is essentially low carbon microalloyed and copper-strengthened high strength steel. It is one of the important materials in naval, and others structural applications in which high strength (UTS >1000 MPa) and good toughness can be obtained without impairing weldability by judiciously engineering the microstructure. This steel can provide various strength–toughness combinations over a wide range of plate thickness by different heat treatments. Available literatures concerning the influence of heat treatment on microstructure and mechanical properties are confined to the characterisation of microstructure and the variation in mechanical properties such as tensile strength and impact toughness. Such mechanical property evaluation is insufficient to characterise the mechanical behaviour of the materials. Modern engineering design approach demands a fracture mechanics based characterisation of material behaviour.