Shadow mask support member having high strength and thermal deformation

Abstract

There is disclosed a shadow mask support member for supporting a shadow mask of a Braun tube which member comprises a parallel bonded-type bimetal, and has a high strength and an excellent resistance to thermal resistance. There is also disclosed a method of producing such a support member. The shadow mask support member includes a high-strength, low-expansion alloy plate, and a high-expansion alloy plate which are bonded together on their marginal surfaces, the low-expansion alloy plate having an excellent resistance to thermal deformation, the low-expansion alloy plate consisting essentially, by weight, of 0.1-0.5% C, not more than 1.0% Si, not more than 2.0% Mn, 30-40% Ni, 1.0-5.0% Mo and the balance Fe and incidental impurities, the low-expansion alloy plate having an average thermal expansion coefficient of not more than 6 .times.10.sup.-6 /.degree. C. at 30.degree.-100.degree. C. and a tensile strength of not less than 100 kgf/mm.sup.2 at a room temperature, and the high-expansion alloy plate having an average thermal expansion coefficient of not less than 14.times.10.sup.-6 /.degree. C. at 30.degree.-100.degree. C. and a tensile strength of not less than 110 kgf/mm.sup.2 at a room temperature. Optionally, the low-expansion alloy plate may further contain not more than 10.0% Cr and not more than 10.0% Co, and the content of (Ni+Co) is 30-40%.