LATER STAGE OF REVERSE TRANSFORMATION IN LOW-CARBON LOW ALLOY STEEL.

Abstract

In continuation of previous investigations of 0. 12C-3. 5Ni-0. 35Mo steel with less than 0. 0005 and 0. 0020% B, respectively, the process of the formation of austenite in the later stage of reverse transformation was investigated. The usual reverse transformation, which accompanies the austenite grain refinement, occurred in the boron-free steel whereas gamma prime transformation was predominant in the 0. 002% B steel and no significant changes of austenite grain size were observed. It is suggested that whether gamma prime transformation or usual reverse transformation is predominant is controlled by the rate of recrystallization of austenite.