Acicular Ferrite Transformation under the Influence of V Precipitates

Abstract

Grain refinement is used as a strengthening mechanism in steels, because it enhances both strength and toughness at the same time. This knowledge was, and still is, a strong driving force for the development of new heavy forming practices where final grain has to be very small. But there is always the option of taking advantage of phase transformations that due to their particular mechanism of transformations and intermediate transformation temperatures, give as a natural consequence a low aspect ratio as well as a chaotic distribution, which finally leads to an excellent combination of mechanical properties. This is the case of acicular ferrite (AF) and bainitic ferrite (BF). This paper deals with the enhancement of AF transformation by the presence of V rich precipitates in a low carbon V microalloyed steel.