Steel cord for rubber enhancement and manufacturing method therefor

A method for manufacturing a steel cord for rubber reinforcement, the method comprising:

• performing sequential plating on a surface of a steel wire in the order of Cu→Co→Zn;
• performing a primary diffusion, for concentration gradient of Co, by subjecting the sequentially plated steel wire to high-frequency induction heating using 1-500 MHz;
• and
• performing a secondary diffusion, following the primary diffusion, by medium-frequency induction heating using 10-500 KHz;
• wherein the sequentially plated steel wire subjected to the primary diffusion and the secondary diffusion comprises a ternary alloy plating layer of Cu—Co—Zn and has a concentration gradient in which the Co content ratio (Co/(Cu+Zn+Co)) in a region from the an outside surface of the plating to ¼ of the plating layer is 40% or more and up to ½ of the plating layer 20% or more compared with the Co content ratio in the entire region of the plating layer.