A diffusionless shear-type martensitelike mechanism of the formation of austenite in a pearlitic steel during laser heating

It is shown by transmission electron microscopy and electron diffraction that, under ultrarapid laser heating, the α-γ phase transformation in a pearlitic carbon steel can proceed by a shear-type diffusionless mechanism that results in the deformation of cementite platelets. The crystallographic characteristics of shear planes involved in the α-γ transformation are determined.