| abstract |
Disclosed is an unalloyed steel wire with high strength and excellent resistance to longitudinal cracking, a steel for the unalloyed steel wire, and a method for producing the steel. The unalloyed steel wire is characterized in that the essential components are C (0.65-1.2 percent by weight), Si (0.1-2.0 percent by weight), Mn (0.2-2.0 percent by weight) and Fe, the main phase is pearlite and the ferrite area ratio is less than 0.40% in the surface layer to a depth of 50 μm from the surface. The unalloyed steel wire may also contain B (0.0003-0.0050 weight percent), Ti (less than 0.030 weight percent) and N (less than 0.0050 weight percent), the amounts of B, Ti and N of equation (1) are sufficient, DOLLAR A 0.03 6 B / (Ti / 3.43 - N) 6 5.0. DOLLAR A The steel wire obtained in the usual way contains ferrite in an amount of less than 0.40% by weight in its surface layer. This low proportion of ferrite is responsible for good resistance to longitudinal cracking, since the longitudinal cracking starts from ferrite. |