| 摘要 |
PROBLEM TO BE SOLVED: To provide a copper plated steel sheet, excellent in copper penetration resistance and grain coarsening resistance and used for the manufacture of a double rolled pipe, and its production. SOLUTION: This copper plated steel sheet is constituted of a steel sheet as basis material, having a composition consisting of, by weight, 0.03-0.08% C, <=0.1% Si, 0.05-0.5% Mn, 0.015% P, <0.015% S, 0.03-0.08% sol.Al, 0.003-0.008% N, and the balance Fe with inevitable impurities, and a copper plating layer applied to its surface. This steel sheet as basis material has a surface layer part of 50-100μm layer thickness, in which fine AlN precipitates are densely dispersed. This copper plated steel sheet can be produced by cold-rolling a hot rolled steel plate of a slab having the above chemical composition at 50-90% draft, subjecting the resultant cold rolled steel sheet to annealing treatment in an N2 -H2 gaseous mixture of >=2vol.% H2 concentration in the temp. region between the recrystallization temp. and 850 deg.C, and then applying copper plating.
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