Steel wire and hot-rolled wire material

Abstract

A steel wire which has a component composition comprising 0.10 to 0.60% of C, 0.01 to 0.50% of Si, 0.20 to 1.00% of Mn, 0.030% or less of P, 0.050% or less of S, 0.85 to 1.50% of Cr, 0.001 to 0.080% of Al, 0.0010 to 0.0200% of N, and a remainder made up by Fe, impurity elements and arbitrary elements, and includes a center axis of the steel wire, wherein, in a cross section parallel to the center axis, 95% by area or more of the metal structure is made up by ferrite and a spherical carbide, ferrite grains have an average grain diameter of 10.0 to 30.0 [mu]m, spherical carbide particles each having an equivalent circle diameter of 0.1 [mu]m or more have an average aspect ratio of 2.5 or less, and the number of the spherical carbide particles each having an equivalent circle diameter of 0.1 [mu]m or more is 1.5*10<6>*[C] to 7.0*10<6>*[C] particles / mm2, wherein [C] represents the content (% by mass) of C in the steel wire.

Description

Technical field [0001] The present invention relates to a steel wire and a hot rolled wire. [0002] The present application claims priority in Japan, 2019-092640, proposed in Japan, issued by Japan, 2019, and references its content. Background technique [0003] Since cold forging is excellent in size accuracy, productivity, etc. in the molded article, therefore in the molding of mechanical components such as steel bolts, screws, nuts, cold forging is replacing conventional hot forging. Further, the components such as bolts, nuts are used in structural use, and therefore, all alloy elements such as C, Mn, CR are added to impart intensity. [0004] However, if the alloy element content is increased, the deformed resistance of the steel is increased or the ductility is lowered, so there is an increase in the load of the metal mold while the metal mold is increased, and the molding unit is generated on the molding unit. And other issues. [0005] In addition, in recent years, the c...

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Problems solved by technology

[0004] However, if the content of alloy elements increases, the deformation resistance of the steel material increases or the ductility decreases, so the load on the metal die increases during cold forging, and the wear and damage of the metal die occur, and processing cracks occur on the formed part. And other issues

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