Influence of heat treatment parameters on structure and mechanical properties of an HSLA-100 steel

Abstract

An HSLA-100 steel received from the US Naval Research Laboratory has been characterised. The effects of heat treatment parameters such as austenitisation time and temperature, tempering time and temperature on mechanical properties have been studied. The microstructures resulting from different heat treatment conditions have been correlated with mechanical properties through SEM and TEM studies. Quantitative relationships have been developed between mechanical properties and the operational variables within a narrow range of variation of the variables by statistical design of experiments. A quantitative relationship has also been developed for the same for a wider experimental region through curve fitting technique. The best combination of strength and low-temperature toughness was obtained in the region of 700 °C tempering temperature and 0.3 - 0.4 h tempering time.