| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high carbon steel wire rod capable of production of a steel wire with high strength and high ductility by specifying carbon content and also specifying the average pearlite nodule size in the surface layer part and that in the inner part, respectively. SOLUTION: The pearlite nodule structure in the surface layer part 1a of a high carbon steel wire rod is regulated so that it is finer than that in the inner part 1b. To be concrete, the average pearlite nodule size in the surface layer part 1a is regulated to <3.0μm, preferably <2.8μm, and that in the inner part 1b is regulated to >=3.0μm, preferably 3.0-<4.0μm. By this procedure, the substantial strain of ferrite in the surface layer part of a steel wire after wire drawing is decreased. Further, the average carbon content of the steel wire rod is regulated to 0.70-0.90 wt.%, preferably 0.80-0.87 wt.%, taking the strength, productivity, and economical efficiency of a steel wire to be obtained into consideration, and also the tensile strength of the steel wire rod is regulated to 1225-1323 MPa.
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