Effect of Austenitising Temperature and Cooling Condition on Mechanical Properties of Low Carbon Boron Containing Steel

The hardening behaviour of boron free and boron added low carbon aluminium killed steel was studied through heat treatment experiments by varying the austenitising temperatures and cooling condition. These parameters have been found to significantly influence the segregation and precipitation of boron and thereby final mechanical properties of steel. Strong dependence of cooling condition on effectiveness of boron as hardener is noticed; rather below a critical cooling rate boron has softened the steel. Strain hardening exponent (n) has been correlated with hardening / softening behaviour of boron.