Patent ID: 8328961

Claim:
An iron-nickel alloy strip that comprises, in % by weight: 32≦Co+Ni≦45%, 0≦Co≦6.5%, 0≦Cr≦6.5%, Cu≦3%, Si≦0.5%, Mn≦0.75%, 40≦Ni≦45%, iron and the inevitable impurities resulting from smelting, wherein the strip has a recrystallized volume fraction of from 3 to 97% and a thickness of the strip is smaller than 0.5 mm, wherein the strip is obtained by a process comprising: subjecting the strip to a cold-rolling operation to obtain a cold-rolled strip with a target thickness, then, optionally, if the target thickness is not obtained, subjecting the cold-rolled strip to an annealing heat treatment in order to obtain a fully recrystallized strip, then to an additional cold-rolling operation to cold-roll the fully recrystallized strip, wherein the annealing and the additional cold rolling are optionally repeated until the target thickness is obtained, and subjecting the obtained strip with the target thickness to a final partial recrystallization treatment in order to obtain a strip having the recrystallized volume fraction of from 3 to 97%, wherein: the final partial recrystallization heat treatment is carried out at a temperature of from 650 to 825° C. where a duration time is shorter than 10 seconds when the temperature is higher than 710° C.; and no further cold-rolling is applied to the strip after the final partial recrystallization heat treatment.