Deformation-induced phase transitions in a high-carbon steel

The methods of Mössbauer spectroscopy, X-ray diffraction analysis, electron microscopy, magnetostructural analysis and durometry were used to examine structural and phase transitions in a high-carbon pearlitic steel of the formula Fe–1.37mass% C (U13) during cold deformation (300 K) by compression shear in Bridgman anvils. The dissolution kinetics of a cementite having different morphologies was established. A supersaturated solid solution of carbon in BCC iron, an austenite with a high carbon concentration, and metastable ε- and χ-carbides were formed during dissolution of the pearlite. Strengthening of the U13 steel depended on the formation of solid solutions of carbon in iron and precipitation of dispersed metastable carbides facilitating pinning of dislocations.