Wire rod excellent in wire-drawing workability and method for producing same

Abstract

Disclosed are a wire rod and a method therefor. The wire rod is excellent in wire-drawing workability, insusceptible to wire break in spite of an increase in wire-drawing rate, and reduction of area, and capable of extending a die life by suppressing die wear. The wire rod is made of steel containing C: 0.6 to 1.1%, Si: 0.1 to 2.0%, Mn: 0.1 to 1%, P: not more than 0.20%, S: not more than 0.20%, N: not more than 0.006%, Al: not more than 0.03%, and O: not more than 0.003%, the balance including Fe, and unavoidable impurities. Further, the wire rod comprises a pearlite structure wherein an area ratio of a second-phase ferrite is not more than 11.0%, and a pearlite lamellar spacing is not less than 120 μm.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to a wire rod excellent in wire-drawing workability, out of which a drawn wire product, such as a steel cord, beading wire, PC steel wire, spring steel, can be efficiently produced with high productivity, and a method for producing the same. [0002] In most cases of producing a drawn wire product, such as a steel cord, a drawing process is applied to a wire rod serving as material for the wire product in order to make adjustment in size and quality (physical properties), and therefore, it is extremely useful from the viewpoint of enhancement in productivity, and so forth to improve wire-drawing workability of the wire rod. In this connection, if improvement on wire drawing workability is implemented, this will not only improve productivity, due to an increase in drawing rate and a decrease in the number of drawing passes, but also provide many benefits such as reduction in wear and tear of draw dies. [0003] Accordingly, in a pe...

AI Technical Summary

Benefits of technology

[0006] Under circumstances described as above, the invention has been developed, and it is therefore an object of the invention to provide a wire rod excellent in wire-drawing workability, insusceptible to wire break in spite of an increase in wire-drawing rate, and reduction of area, and capable of extending a die life by suppressing die wear, and a method for producing the same.

[0010] The wire rod according to the aspect of the invention may further contain at least one element selected from the group consisting of not more than 5 ppm Mg, not more than 5 ppm Ca, and not more than 1.5 ppm REM in order to soften oxides and enhance the wire drawing workability. Still further, the wire rod according to the invention may contain not more than 15 ppm B in order to enhance hardenability.

[0012] The inventor, et al. have found out to their surprise that a wire rod excellent in wire-drawing workability, insusceptible to wire break, and capable of extending a die life by suppressing die wear, can be obtained by specifying the respective contents of C, Si, Mn, P, S, N, Al, and O while controlling the area ratio of the second-phase ferrite and the pearlite lamellar spacing. With the use of the wire rod described, it will become possible to increase a wire-drawing rate, and reduction of area, thereby enabling productivity to be further enhanced.

Problems solved by technology

However, a rise in wire-drawing rate, and an increase in reduction of area per one pass cause degradation in ductility of a drawn wire product, and deterioration in die life.

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