HARDENED FE-NI ALLOY FOR MAKING INTEGRATED CIRCUIT GRIDS AND METHOD FOR MAKING SAME

摘要

A method of making a Fe-Ni strip whose chemical composition comprises, by weight: 36% <=Ni+Co<=43%; 0%<=Co<=3%; 0.05%<=C<=0.4%; 0.2%<=Cr<=1.5%; 0.4%<=Mo<=3%; Cu<=3%; Si<=0.3%, Mn<=0.3%; the rest being iron and impurities, the alloy having an elastic limit Rp0.2 more than 750 Mpa and a distributed elongation Ar more than 5%. The alloy is optionally recast under slag. The strip is obtained by hot-rolling above 950° C., then cold-rolling and carrying out a hardening treatment between 450° C. and 850° C., the hardening heat treatment being preceded by a reduction of at least 40%. The invention is useful for making integrated circuit support grids and electronic gun grids.