EFFECT OF AUSTENITIC GRAIN SIZE ON THE PHASE TRANSFORMATION OF A NOVEL 6.5% Cr STEEL FOR FORGED COMPONENTS

In this paper the effect of quenching and tempering (Q&T) thermal treatment on mechanical properties of a novel 6.5% Cr steel for forged components is studied. The main innovation is in the increased hardenability following the higher Cr content with respect to the more common 5% Cr steel allowing to lower the content of other chemical elements aimed to achieve the target mechanical properties. Following to the high intrinsic hardenability of such steel based on the Cr content a poor effect of prior austenite grain size should be expected after quenching. Aim of this work is to evaluate such effect and to analyse the dependence of mechanical properties on it.