| 摘要 |
PROBLEM TO BE SOLVED: To obtain a wire rod excellent in wire drawability and to provide, with high productivity in superior yield, an extra fine steel wire using the wire rod as a material and a stranded steel wire formed by stranding the extra fine steel wire. SOLUTION: This wire rod contains 0.0005-0.02 wt.% S. In this wire rod, the sum of the area ratio of pro-eutectoid cementite and that of martensite in the structure is regulated to <=5%. Moreover, in the longitudinal section in a longitudinal direction, the proportion, by number, of sulfide inclusions having a width W1 of >=0.364×dμm to all nonmetallic inclusions is regulated to 50-90%, and also the proportion, by number, of nonmetallic inclusions having a width W2 of >=1.5×dμm to all nonmetallic inclusions is regulated to <=10%. At this time, (d) is the diameter (mm) of the steel wire rod.
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