LOW THERMAL EXPANSION ALLOY THIN SHEET AND ITS PRODUCTION METHOD

摘要

A low thermal expansion alloy thin sheet containing 30 to 34% by mass of Ni, 2 to 6% by mass of Co., Ltd., and the balance substantially of Fe and having an accumulation degree at (200)-face of below 50%. The low thermal expansion alloy thin sheet is produced by a method wherein the method comprises the step of repeating one or more times cold rolling and recrystallization annealing of a hot rolled sheet containing the above-mentioned components and the step of performing cold rolling after the last recrystallization annealing, the cold rolling reduction ratio immediately before the last recrystallization annealing is 65% or less, and the temperature of the last recrystallization annealing is 1100 °C or less. The thus produced low thermal temperature alloy sheet is excellent in etching characteristics, particularly in etching dimension precision, and therefore preferable to the shadow mask of a cathode-ray tube.