Patent ID: 6893739

Claim:
A steel plate having an electrolytic galvanized coating thereon with shield effect against time-varying electromagnetic field at low frequency having a yield strength of 18 kg/mm 2 or higher, and an elongation of 40% or higher, comprising C in an amount of 0.003% by weight or less, N in an amount of 0.003% by weight or less, S in an amount of 0.009% by weight or less, C, N and S in an amount of 0.015% by weight or less in total; Mn in an amount of 0.1 to 1.0% by weight; Si in an amount of 0.5% by weight or less; Al in an amount of 1.0% by weight or less; P in an amount of 0.06% by weight or less; and Fe for the remainder, and inevitably present elements; and wherein the electrolytic galvanized coating is overlaid by a layer of far infrared radiation emitting powder which has a radiation efficiency of 0.9 with a thickness of 15-60 μm.