Transformations of Supercooled Austenite in Promising High-Hardenability Machine Steels

Abstract

We study special features of the transformation of supercooled austenite under the continuous cooling of Si – Mn steels with reduced contents of nickel as compared with traditionally used machine steels. The temperature ranges of the phase and structural transformations running under the conditions of heating and cooling of steels are determined by the dilatometric method. We plot the thermokinetic diagrams of transformations of supercooled austenite. The microstructural components formed in the investigated steels are analyzed both qualitatively and quantitatively. We also propose the chemical compositions of promising steels characterized by a high stability of supercooled austenite and high hardenability.