Coefficient of thermal expansion of the 20 of production manner null

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a strip made of an Fe-Ni alloy which exhibits good creep strength and blackenability.;SOLUTION: This production method is to produce a strip made of a γ' and/or γ" structure hardening type Fe-Ni alloy whose thermal expansion coefficient at 20 to 150°C is lower than 7×10-6/K. In this method, a thermal strip produced from a semi-finished product by hot rolling or from molten metal by direct casting is subjected to softening and tempering operation at 950 to 1,200°C. Successively, the strip is subjected to rapid cooling and, optionally, to pickling operation to obtain a softened strip. The strip is subjected to cold rolling at a reduction ratio of ≥5% to produce a strip. The strip is subjected to recrystallization annealing operation in an inert or reducing atmosphere performed for a residence time of 30 sec to 5 min at 900 to 1,200°C on a run, or performed by soaking for 15 min to 5 hr at 900 to 1,050°C in a stationary way. The strip is successively cooled to ≤500°C at a sufficient cooling rate for preventing the formation of hardening precipitates.;COPYRIGHT: (C)2002,JPO