Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Kabushiki Kaisha Kobe Seiko Sho (kobe Steel, Ltd.)

Kenji Ochiai

Nobuhiko Ibaraki

Takaaki Minamida

Mamoru Nagao

Hiroshi Yaguchi

Katsuji Mizutani

Koichi Makii

Mamoru Murahashi

Kozo Katsube

Atsushi Inada

Yasuhiro Oki

Shinzo Ashida

Noriaki Hiraga

Sakae Wada

Yoshihiro Mitani

Tamotsu Shohzaki

High-strength steel wire excelling in resistance to strain aging embrittlement and longitudinal cracking, and method for production thereof

A wire rod for drawing which is superior in drawability as well as twisting characteristics, and a method for producing the wire rod. The wire rod is characterized in that the raw material thereof is a eutectoid steel or hypereutectoid steel containing 0.1-2.0 mass % Si and 0.2-2.0 mass % Mn and the pearlite structure therein accounts for no less than 80 area % of microstructure and the maximum length of ferrite as the second phase therein is no larger than 10 &mgr;m. The wire rod is produced by drawing with a true strain of 1.5 or above and subjecting the wire rod to patenting at a heating temperature defined by a specific equation.

Wire rod for drawing superior in twisting characteristics and method for production thereof

High-carbon steel wire superior in resistance to longitudinal cracking, steel product for the same, and process for production of the same

Disclosed are a steel wire rod for manufacturing a fine steel wire excellent in drawability, strength and toughness in which the contents of components such as C, Si, Mn, P, S, Al, Cu are specified, the contents of one or more of elements selected from a group consisting of Cr, W, Ni and Mo are also specified, and in which the balance is essentially Fe and inevitable impurities and for which, the composition of non-metallic inclusions of oxides is also specified; a fine steel wire obtained by drawing of the steel wire rod; and a twisted wire cord made by twisting of the fine steel wires. Further, disclosed is a die schedule for manufacturing the above fine steel wire. Thus, there can be provided a steel wire rod with excellent drawability and which does not break during drawing; a fine steel wire excellent in strength and toughness obtained from the steel wire rod; and a twisted wire cord obtained by twisting together lengths of the fine steel wires.

Hot rolled steel wire rod, fine steel wire and twisted steel wire

The fine steel wire according to the present invention has a high strength and high toughness, which is used as a rubber reinforcing material for a belt cord or tire cord, or as missile wires. Such a fine steel wire can be obtained by drawing a wire rod for a fine steel wire properly adjusted in its composition and structure, while applying working strain such that the total reduction of area in the final wire drawing step becomes 95% or more.

Wire rod for high strength and high toughness fine steel wire, high

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Kobe, Japan

Kenji Ochiai