摘要 |
Process for manufacturing a strip made of an Fe-Ni alloy of the "gamma' and/or gamma'' structural hardening" type, the thermal expansion coefficient between 20 C. and 150 C. of which is less than 7x10-6/K, in which a hot strip is manufactured either by hot rolling a semi-finished product or by direct casting of a thin strip which is optionally lightly hot-rolled, and the hot strip is subjected to a softening annealing operation consisting of a soak between 950 C. and 1200 C. followed by rapid cooling and optionally a pickling operation, in order to obtain a softened strip; a cold-worked strip is manufactured by cold rolling the said softened strip, with a reduction ratio of greater than 5%; and the cold-worked strip is subjected to a recrystallization annealing operation in an inert or reducing atmosphere, carried out either on the run with a residence time between 900 C. and 1200 C. of between 30 s and 5 min, or statically with a soak at a temperature of between 900 C. and 1050 C. fo r a time of between 15 min to 5 h, followed by cooling down to a temperature below 500 C. at a cooling rate sufficient to prevent the formation of hardening precipitates. Strip made of an Fe-Ni alloy.
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