Nippon Yakin Kogyo Co., Ltd.

Other

Hippon Yakin Kogyo Co., Ltd.

Tatsuya Itoh

Tsutomu Omori

Shigeru Hirata

Taizo Sato

Jun Agari

Syun-ichi Morita

A Fe&#x2014;Ni based permalloy comprises Ni: 30-85 wt %, C: not more than 0.015 wt %, Si: not more than 1.0 wt %, Nin: not more than 1.0 wt %, P: not more than 0.01 wt %, S: not more than 0.005 wt %, O: not more than 0.0060 wt %, Al: not more than 0.02 wt % and, if necessary, not more than 15 wt % of at least one selected from the group consisting of Mo, Cu, Co and Nb within a range of not more than 20 wt % in total.

Fe-Ni based permalloy and method of producing the same and cast slab

A Fe&#x2014;Ni based permalloy comprises Ni: 30-85 wt %, C: not more than 0.015 wt %, Si: not more than 1.0 wt %, Mn: not more than 1.0 wt %, P: not more than 0.01 wt %, S: not more than 0.005 wt %, O: not more than 0.0060 wt %, Al: not more than 0.02 wt % and, if necessary, not more than 15 wt % of at least one selected from the group consisting of Mo, Cu, Co and Nb within a range of not more than 20 wt % in total.

A Fe&#x2014;Ni based permalloy comprises Ni: 30&#x2013;85 wt %, C: not more than 0.015 wt %, Si: not more than 1.0 wt %, Mn: not more than 1.0 wt %, P: not more than 0.01 wt %, S: not more than 0.005 wt %, O: not more than 0.0060 wt %, Al: not more than 0.02 wt % and, if necessary, not more than 15 wt % of at least one selected from the group consisting of Mo, Cu, Co and Nb within a range of not more than 20 wt % in total.

Fe&#x2014;Ni based permalloy and method of producing the same and cast slab

A Fe&mdash;Ni based permalloy comprises Ni: 30-85 wt %, C: not more than 0.015 wt %, Si: not more than 1.0 wt %, Mn: not more than 1.0 wt %, P: not more than 0.01 wt %, S: not more than 0.005 wt %, O: not more than 0.0060 wt %, Al: not more than 0.02 wt % and, if necessary, not more than 15 wt % of at least one selected from the group consisting of Mo, Cu, Co and Nb within a range of not more than 20 wt % in total.

The present invention aims at providing a sophisticated segregation reducing technique which a conventional technique cannot achieve by finding the relationship between the casting structure and the segregation of components at the time of solidification and the heat treatment conditions. That is, the present invention aims at providing material for shadow masks which exhibits excellent quality with respect to streaks. A material for a shadow mask of the present invention is formed of a casting slab for preparing the shadow mask which comprises an Ni&mdash;Fe alloy containing 30 to 45% of Ni. The casting slab has a cast structure comprising a columnar crystal and/or a chill crystal in an amount of 99% or more. In particular, it is preferred that the casting slab contains no equiaxed crystal. To this end, such casting slab is prepared by a continuous casting method in which casting operation is carried out with no electromagnetic stirring and with maintaining a melt temperature of the non-solidificated part in the slab at a temperature equal to or more than the liquidus thereof. Further, the resultant slab is subjected to a heat treatment at a temperature for a time such that the K value becomes 150 &mgr;m or more, to thereby diffuse the segregation of Ni.

Casting slab for shadow mask, method for heat treatment thereof and material for shadow mask

It is a Fe&mdash;Ni based shadow mask material of Fe&mdash;Ni alloy or Fe&mdash;Ni&mdash;Co alloy used as a material for a color television cathode tube or the like, and relates to a material wherein the material has a texture that an X-ray intensity ratio Ir of cubic orientation (100)<001> to twinning orientation (221)<212> thereof in a (111) pole figure is a range of 0.5-5:1 and segregation of Ni, Mn or the like is less, and a section cleanness defined according to JIS G0555 is made to be not more than 0.05% to reduce the occurrence of streak or mottling in the etching.

Growing community of inventors

Kanagawa, Japan

Tatsuya Itoh