Nippon Steel Corporation

Kunishige Kaneko

Satoshi Nishimura

Kunio Watanabe

Takashi Furukawa

Nagayasu Takemoto

Itaru Imabayashi

Mamoru Tashiro

An iron/copper/chromium alloy material for a high-strength lead frame or pin grid array, which comprises 20 to 90% by weight of Cu and 2.5 to 12% by weight of Cr, with the balance being mainly iron, and which has an average grain size number of at least 10 in each of the iron/chromium phase and the copper phase, is prepared by continuous casting, cold-working, and aging.

Iron/copper/chromium alloy material for high-strength lead frame or pin

A method for producing a low alloy hot rolled steel strip or sheet comprising hot rolling a steel slab at a finishing temperature not higher than the Ar.sub.3 transformation temperature plus 60.degree. C. and cooling and coiling the hot rolled strip at a temperature not higher than 500.degree. C. The steel slab contains not more than 0.20% carbon, 0.50 to 2.50% manganese and 0.05 to 1.0% chromium and optionally contains not more than 1.0% silicon, the balance being iron and unavoidable impurities. The resultant strip or sheet has a high tensile strength of not less than 40 kg/mm.sup.2, a low yeild ratio of not more than 70% and an excellent total elongation of not less than 25%.

Method for producing low alloy hot rolled steel strip or sheet having

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Tokyo, Japan

Kunishige Kaneko