High-temperature magnetisation measurements on the pearlite transformation kinetics in nearly eutectoid steel

• Published in: Journal of magnetism and magnetic materials 2004, Vol.268 (1), p.40-48
• Main Authors: van Dijk, N.H., Offerman, S.E., Klaasse, J.C.P., Sietsma, J., van der Zwaag, S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnetisation; Materials science; Metals. Metallurgy; Pearlite; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase transformation; Physics; Steel
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(03)00427-X

The isothermal transformation kinetics of the austenite to pearlite transformation in (nearly) eutectoid steel was studied by in situ magnetisation measurements at high temperatures. In eutectoid steel the high temperature austenite (γ-Fe) phase decomposes into pearlite, which consists of a lamellar structure of ferrite (α-Fe) and cementite (Fe 3C). Below the Curie temperature of ferrite T C=1043 K the ferrite phase fraction can be probed by the magnetisation measurements. For our nearly eutectoid steel not only pearlite but also a small fraction of pro-eutectoid ferrite is formed. The transformation kinetics of the pearlite and the pro-eutectoid ferrite is studied by magnetisation measurements as a function of the isothermal transformation temperature and compared with the results from additional dilatometry measurements. The transformation kinetics was found to vary over four orders of magnitude over the range of transformation temperatures and was compared with model predictions.