Vieillissement
Metallurgy; Materials; Painting
1. General property of stable systems whose
mechanical, chemical, etc. characteristics,
evolve with time.
2. The variation according to time, at room
temperature or during slight heating, of the
properties of a metal having undergone
preliminary processing such as quenching and/or
cold hammering. Aging is:
natural or spontaneous (naturel ou spontané)
if it occurs at room temperature and without
intervention of other factors (it is sometimes
improperly called spontaneous temper);
artificial (artificiel ou accéléré) if it is
hastened by heating at moderate temperature, by
refrigeration, temperature oscillations (inside a
gap which may or not may include room
temperature), by mechanical action, or any other
combination of these means. Its objective is to
quickly obtain modifications of properties which
would have occurred spontaneously at a room
temperature but only after a longer time. Bluing
(improperly called blue annealing) is sometimes
used to accelerate artificial aging.
3. Progressive degeneration of a paint film, due
to exposure to atmospheric, chemical and
physicochemical aggressive agents.
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