| 摘要 |
PURPOSE: To enhance the separation resisting performance of a steel wire by specifying both mean thickness and standard deviation of thickness distribution of the steel wire and applying brass plating, in which copper and zinc whose weight % is specified are used, to a wire rod consisting of a pearlite. CONSTITUTION: Uneveness 2 is formed in many places of the surface of a steel material 1 for forming a steel cord, and plating 3 is applied in correspondence to the uneveness 2. In this case, the mean thickness of the plating 3 is specified as 50nm<=X<=150nm, while the standard deviation (σ) of the thickness distribution is specified as 10nm<=σ<=30nm. In preparing the wire steel 1, carbon steel, in which carbon content is 0.60 to 0.95% in weight %, undergoes heat treatment to become hypo-eutectoid or eutectoid steel consisting of two phases made up of (pearlite + cementite) or (ferrite + cementite). After this, the wire material 1 is drawn under the 'WET' condition to become a wire rod having the diameter of 0.15 to 0.45mm. In addition, the surface of the wire rod is plated by means of a brass plating method, in which 60 to 70% (in weight) of copper and 40 to 30% of zinc are contained and sometimes cobalt or nickel, whose content in total is less than 10%, is added. |
