| 摘要 |
PURPOSE:To obtain a low thermal expansion alloy having superior strength in a hot-worked state by adding prescribed amounts of Al and by controlling the amounts of C, Si and Mn in inevitable impurities in a low thermal expansion alloy consisting of Ni, Fe and inevitable impurities. CONSTITUTION:The low thermal expansion alloy consists of, by weight, 35-45% Ni, 1-5% Al and the balance Fe with inevitable impurities and contains, if necessary, <=5% W, in which the amounts of C and Si and/or Mn among the inevitable impurities are limited to <=0.05% and <=1%, respectively. The above alloy has an average coefficient of thermal expansion as low as <=about 7X10<-6>/ deg.C and moreover it has a tensile strength as high as >=about 60kgf/mm<2> even in the hot-rolled state, not to mention in the cold-rolled state. Accordingly, this alloy has high strength even if the stages of cold working and repeated annealings after hot working are omitted, so that shortening of manufacturing time as well as simplification of manufacturing process can be attained.
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