https://escholarship.org/content/qt74g541qk/qt74g541qk.pdf

Orientation relationships in precipitation systems

A rationalisation of shear transformations in steels

This paper is concerned with the direct transformation of austenite at high temperatures to form ferrite and alloy carbide dispersions. The ferrite/austenite interfaces vary from high energy random boundaries to low energy planar boundaries which grow by step propagation, while the alloy carbide morphologies include a pearlitic form, fine fibers and fine banded arrays of particles. It is shown that these morphologies are closely related to the mode of growth of the ferritic matrix. The role of various alloying elements on the carbide dispersion is examined, and the effects of other metallurgical variables on the banded dispersions are discussed, including factors which influence the dispersion stability. The mechanical properties of directly transformed alloy steels are shown to depend largely on the ferrite grain size and the state of the carbide dispersion. Micro-alloyed steels subjected to controlled rolling provide an excellent example of the achievement of high strength and toughness levels by control of these variables. The paper finally attempts to show how such benefits can be achieved in low and medium alloy steels, and in particular where resistance to creep failure at elevated temperatures is an important property.

Transformation from austenite in alloy steels

Published experimental data on the thickness of bainite plates in silicon-rich steels have been analysed in order to develop a quantitative model for the plate-thickness. It is found that the strength of the austenite, and the chemical free energy change accompanying transformation, are by far the most important factors influencing plate-thickness. The transformation temperature does not have any independent effect within the limits of the analysis. These trends are expected from a metallurgical point of view and are discussed in the context of the mechanism of transformation.

Estimation of bainite plate-thickness in low-alloy steels

M.G. Hall

Papers

The fine structure F. C. C. /B. C. C. boundaries in a Cu-0. 3% Cr alloy

Application of the “0” lattice calculation to f.c.c./b.c.c. interfaces

The Nature of the Barrier to Growth at Partially Coherent FCC:BCC Boundaries

The Watson-McDougall shear: Proof that Widmanstatten ferrite cannot grow martensitically

Nucleation kinetics of the massive transformation in CuZn in the presence and absence of special orientation relationships