Strain-Induced FCC(γ)→HCP(ε) Phase Transformation and Active Slip Systems

• Published in: Transactions of the Japan Institute of Metals Vol. 18; no. 3; pp. 169 - 177
• Main Authors: Ueda, Syuzo, Fujita, Hiroshi
• Format: Journal Article
• Language: English
• Published: The Japan Institute of Metals 1977
• ISSN: 0021-4434; 2432-4701
• DOI: 10.2320/matertrans1960.18.169

Relations between the formation of strain-induced ε-phase and the active slip systems have been systematically studied by optical and transmission electron microscopy on single crystals of austenitic Fe–Mn–C alloy. The results obtained are summarized as follows: (1) In crystals oriented for a single slip system, the ε-phase plates are formed only along the well-developed primary slip bands in general. In this case, the dislocations belonging to the conjugate or cross slip system are locally activated. (2) The ε-phase plates are formed along the primary and conjugate slip bands in crystals oriented for a double slip system, and along the slip bands of all active slip systems in crystals oriented for a multiple slip system. In these crystal, the slip bands along which the ε-phase plates are formed are generally terminated on other slip bands of different slip systems, respectively. Furthermore, the kinked stacking fault with a stair-rod dislocation is frequently observed by electron microscopy. Based on these results, the orientation dependence of the formation of ε-phase is discussed.