Kinetics of anomalous multi-step formation of lath martensite in steel

Matteo Villa, Karen Pantleon, Michael Reich, Olaf Kessler, Marcel A. J. Somers

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A steel containing 16wt.% Cr, 5wt.% Ni and 3wt.% Cu was transformed into martensite by applying isochronal, i.e. constant rate, cooling followed by isothermal holding. The formation of martensite was monitored with dilatometry. A series of retardations and accelerations of the transformation was observed during isochronal cooling for cooling rates ranging from 1.5 to 50Kmin−1. The cooling rate in the isochronal stage was observed to influence the transformation rate in the isothermal stage. Electron backscatter diffraction was applied to determine the morphology of the martensite, which was of lath type, and to investigate the microstructure of the material. No influence of the cooling rate on the scale of the microstructure was observed. The series of retardations and accelerations of the transformation is interpreted in terms of the combined effect of the strain and interfacial energy introduced in the system during martensite formation, which stabilizes austenite, and autocatalytic nucleation of martensite.
Original languageEnglish
JournalActa Materialia
Volume80
Pages (from-to)468-477
Number of pages10
ISSN1359-6454
DOIs
Publication statusPublished - 2014

Keywords

  • Isothermal martensite
  • Steels
  • Transformation kinetics
  • Dilatometry

Fingerprint Dive into the research topics of 'Kinetics of anomalous multi-step formation of lath martensite in steel'. Together they form a unique fingerprint.

Cite this