| 摘要 |
PURPOSE: A method is provided which manufactures a Bi-S based free-cutting steel wire rod without cracks on the surface of a material to be processed by properly controlling a gradient of pass schedule when rolling the wire rod in a wire rod rolling line. CONSTITUTION: In a method for manufacturing a wire rod by rolling a Bi-S based free-cutting steel heated in a heating furnace in a wire rod rolling line comprising roughing train, intermediate train and finishing train, the method for manufacturing a Bi-S based free-cutting steel wire rod is characterized in that pass schedules at each of the stands are controlled so that pass schedule gradients of each stands £(pass schedule)N+1/(pass schedule)N; where N represents a stand number| in which a temperature of the surface of a free-cutting steel heated in the heating furnace is reduced in the roughing train and intermediate train is in the range of 0.922 to 1.094.
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