3. Relationship between micro and macro residual stresses

3.1 Reminder: effect of carbon on the crystal lattice in the hardened state

The aim of austenitizing is to bring the elements of the steel's chemical composition into solution prior to quenching. We know that the solubility limit of carbon in austenite is much higher than that in the face-centered cubic lattice of ferrite. The richer the face-centered cubic lattice is in carbon and additive elements, the more thermodynamically stable the austenitic phase. This phenomenon is reflected in an increase in the austenite stability range (see TRC and TTT diagrams). After quenching, the result is a non-equilibrium structure known as "martensite", with a centered quadratic lattice characterized by its base (a ² ) and height (c).

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