The influence of manganese and silicon on the precipitation of vanadium carbide in steel

Abstract

Four vacuum-melted steels with a nominal composition of Fe0.12wt.%C0.46wt.%V contained additions of 1.5 wt.% Mn (steel B), 0.3 wt.% Si (steel C) and 1.5 wt.% Mn and 0.3 wt.% Si (steel D). Steel A, with no manganese or silicon additions, was the control steel. After hot rolling, some of the material was drawn to wire, prior to solution treating at 1250°C followed by aging for different times at 650°C.

Resistivity, hardness and metallography were used to follow the precipitation kinetics of vanadium carbide. Alloy carbide precipitation at 650°C was found to start simultaneously with austenite transformation and occurred only in the ferrite phase.

Silicon increased the rate of precipitation by approximately four times, but manganese, other than affecting the rate of austenite transformation, had little influence on the alloy precipitation kinetics.

The combined addition of manganese and silicon resulted in an intermediate rate of transformation which influenced the precipitation kinetics of vanadium carbide.