Peculiar metastable structural state in carbon steel

Abstract

The kinetics of phase transformations at cooling of carbon steel in dependence on the temperature of preliminary annealing T${}_{an}$ is studied. It is shown that the cooling from T${}_{an}$ > A${}_3$ (i. e. above the temperature of ferrite start) with the rate 90 - 100 K/s results in structural state which essentially dependent on T${}_{an}$; at 750${}^0$C < T${}_{an}$ < 830${}^0$C the transformation is of perlite type whereas at T${}_{an}$ > 830${}^0$C the martensitic structure arises. Our results evidence the formation of a special structural state in a certain range of temperatures near and above the boundary of two phase region which is characterized by a substantially nanoscale heterogeneity in carbon distribution, lattice distortions, and magnetic short-range order.

6 pages, 4 figures

References in corpus (2)

• Magnetism and local distortions near carbon impurity in $\gamma$-iron
• Role of magnetic degrees of freedom in a scenario of phase transformations in steel