Carbon in cubic and tetragonal ferrite

  title={Carbon in cubic and tetragonal ferrite},
  author={Harry Bhadeshia},
  journal={Philosophical Magazine},
  pages={3714 - 3725}
  • H. Bhadeshia
  • Published 30 September 2013
  • Chemistry
  • Philosophical Magazine
Abstract It is generally assumed that the phase diagrams and equilibrium thermodynamic data that apply to the conventional Fe-C system, also are relevant to the case where supersaturated ferrite is in contact with austenite. It seems that this may not be correct, since a change in the symmetry of the ferrite unit cell in the presence of excess carbon has the potential to alter the nature of the phase equilibrium. The implications of these discoveries are presented in the context of the early… 
The role of silicon, vacancies, and strain in carbon distribution in low temperature bainite
Further evidence of tetragonality in bainitic ferrite
Abstract There is growing evidence that bainitic ferrite which retains a substantial amount of carbon in solid solution does not have cubic symmetry. We provide additional data on a different
Features of Isothermal Formation of Carbide-Free Bainite in High-Carbon Manganese-Silicon Steel
Change in the stability of overcooled austenite of high-carbon manganese-silicon steel relative to decomposition via the intermediate stage upon isothermal holding and martensitic γ → α
Tetragonality of bcc Phases in a Transformation-Induced Plasticity Steel
In a low-alloyed multi-phase transformation-induced plasticity steel, solute carbon content in polygonal ferrite, bainitic ferrite, and martensite was characterized using site-specific atom probe
Bainite Transformation During Continuous Cooling: Analysis of Dilatation Data
A new approach based on iteration is presented to extract the amount and composition of bainitic ferrite and austenite from the dilatation curve. The carbon concentration of bainitic ferrite
Thermodynamic analysis of the formation of tetragonal bainite in steels
In the articles of Bkhadeshia, a new class of high-strength steels based on the structure of carbidefree bainite with an enhanced carbon content has been developed. According to Bkhadeshia, the main
Critical assessment 20: on carbon excess in bainitic ferrite
For several decades, the question of carbon supersaturation in bainitic ferrite has attracted the attention of physical metallurgists. Originally, this was associated with excess carbon due to the
In situ synchrotron X-ray study of bainite transformation kinetics in a low-carbon Si-containing steel
ABSTRACT The bainite transformation in a low-carbon Si-containing steel has been studied in situ by synchrotron X-rays. While the austenite is homogeneous prior to transformation, the carbon


Tetragonal martensites in ferrous alloys : a critique
Recent experimental results on the axial ratios of bct and fct martensitic phases in both carbon steels and carbon-free ferrous alloys are reviewed, and a number of recent theories are examined. The
Application of first-order quasichemical theory to transformations in steels
AbstractThere are several theoretical and empirical thermodynamic models which adequately describe the equilibrium properties of carbon in ferrite and in austenite (e.g. Refs. 1, 2). These models
Influence of silicon on cementite precipitation in steels
Abstract The mechanism by which relatively small concentrations of silicon influence the precipitation of cementite from carbon supersaturated austenite and ferrite are investigated. It is found that
Model for transition from upper to lower bainite
AbstractAn attempt is made to model the transition from upper to lower bainite in steels, based on the hypothesis that bainitic ferrite grows with a supersaturation of carbon in solid solution. The
Carbon dissolution and diffusion in ferrite and austenite from first principles
We perform density-functional theory (DFT) calculations of carbon dissolution and diffusion in iron, the latter being a typical example of interstitial diffusion. The Kohn-Sham equations are solved