Phase Transformations and Brittleness of ‘Iron–Vacancy’ System in Fields of Elastic Stresses

• Main Author: I. M. Laptev, O. O. Parkhomenko
• Format: Article
• Language: English
• Published: G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine 2010-03-01
• Series: Успехи физики металлов
• Online Access: https://doi.org/10.15407/ufm.11.01.019

The role of elastic stresses in the structure–phase states formation in the ‘iron–vacancy’ and ‘iron–vacancy–carbon’ systems is investigated theoretically. The hysteresis loop describing γ⇆α-transformations in a field of elastic stresses is plotted. The field is normalized as ‘temperature–stress’ one. Its each point corresponds to both the certain elastically stressed state and the concrete phase composition of an alloy. Force conditions of nonequilibrium martensitic γ⇆α-transformations are defined by a vector, which connects any two points lying on opposite branches of the loop. The new approach to definitions of the brittle–ductile-transition temperature for the b.c.c. metals and conditions of superplasticity is proposed. The model can be used for the description of phase transformations and forecasting of serviceability of materials in complex ‘temperature–stress’ fields, including the reactor irradiation.