Nippon Steel Corporation

Nippon Steel & Sumitomo Metal Corporation

Occ Corporation

Namitei Co., Ltd.

Seiki Nishida

Satoru Tanaka

Shingo Yamasaki

Ikuo Ochiai

Hiroshi Oba

Akifumi Kawana

Atsuhiko Yoshie

Satoshi Sugimaru

Akira Takahashi

Wataru Yamada

Daisuke Hirakami

Toshimi Tarui

Kazumi Nishimura

Nariyasu Muroga

Arata Iso

Makio Kikuchi

Toshiyuki Manabe

Makoto Kosaka

Masatsugu Murao

Junji Nakashima

Hitoshi Demachi

Shouichi Ohashi

Yoshitaka Nishikawa

Osami Serikawa

Shingo Yamasaski

Toshiyuki Kajitani

Nobuyuki Komiya

Kouichi Murao

Hiromi Takahashi

Naoshi Hikita

Ken Oyamada

Osami Serkiawa

Syunya Ikebata

Kenichi Nakamura

Susumu Sahara

Atsuhiko c/o Nippon Steel Corporation Yoshie

Toshiyuki; Kajitani

The present invention inexpensively provides with high productivity and good yield a steel rod superior in drawability and a steel wire superior in twistability using the same as a material, that is, draws a high strength steel rod superior in ductility where the chemical components contain C: 0.80 to 1.20%, Si: 0.1 to 1.5%, Mn: 0.1 to 1.0%, Al: 0.01% or less, Ti: 0.01% or less, one or both of W: 0.005 to 0.2% and Mo: 0.003 to 0.2%, N: 10 to 30 ppm, B: 4 to 30 ppm (of which, solute B is 3 ppm or more), and O: 10 to 40 ppm, which has a balance of Fe and unavoidable impurities, has an area percentage of pearlite structures of 97% or more, has a balance of non-pearlite structures, and has a total of the area percentage of the non-pearlite structures and the area percentage of the coarse pearlite structures of 15% or less, to obtain high strength steel wire superior in ductility having a tensile strength of 3600 MPa or more and a number density of voids of lengths of 5 &#x3bc;m or more at the center of 100/mmor less.

Steel rod and high strength steel wire having superior ductility and methods of production of same

There is provided a deformed steel wire includes, as a chemical component, by mass %; C: 0.30% to 1.10%, Si: 0.10% to 1.50%, and Mn: 0.20% to 1.50%, and the balance consists of Fe and unavoidable impurities, in which a metallographic structure is a ferrite-pearlite structure or a pearlite structure, integration degrees of a crystal orientation &#x3c;110&#x3e; in a longitudinal direction of a thickness center area and a surface area are in a range of 2.0 to 4.0, an absolute value of a difference in the integration degree between an inner surface and an outer surface of the surface area is 0.3 or less, an integration degree of a crystal orientation &#x3c;100&#x3e; in a thickness direction of the thickness center area is in a range of 1.2 to 3.8, and a dimensional accuracy index is in a range of 0.5 to 2.0.

Deformed steel wire for protection tube of submarine cable, method for manufacturing same, and pressure-resistant layer

A high strength wire rod in which an area fraction of pro-eutectoid ferrite is 3% or less and an area fraction of pearlite structure is 90% or more, being obtained by subjecting a hard steel wire rod having specified composition to a molten salt patenting treatment directly after hot-rolling or after performing re-austenitization subsequent to hot-rolling.

High strength wire rod excellent in drawability and method of producing same

Provided is a wire rod contains, in mass %: C: 0.6 to 1.1%; Si: 0.1 to 0.5%; Mn: 0.2 to 0.6%; S: 0.004 to 0.015%; and, Cr: 0.02 to less than 0.05%; with a balance including Fe and inevitable impurities in which P is limited to 0.02% by mass or lower and Al is limited to 0.003% by mass or lower; the wire rod has a pearlite in a surface thereof; and, the wire rod has, in a peripheral portion in a cross section thereof, a {110} crystal plane of ferrite in the pearlite, an accumulation degree of the crystal plane being 1.2 or more.

High-carbon steel wire rod exhibiting excellent workability

The invention provides a steel material with satisfactory hydrogen embrittlement resistance, and particularly it relates to high-strength steel with satisfactory hydrogen embrittlement resistance and a strength of 1200 MPa or greater, as well as a process for production thereof. At least one simple or compound deposit of oxides, carbides or nitrides as hydrogen trap sites which trap hydrogen with a specific trap energy is added to steel, where the mean sizes, number densities, and length-to-thickness ratios (aspect ratio) are in specific ranges. By applying the specific steel components and production process it is possible to obtain high-strength steel with excellent hydrogen embrittlement resistance.

High-strength steel material with excellent hydrogen embrittlement resistance

The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is hot rolled, the hot-rolled steel is coiled in a specified temperature range, and the coiled steel is subjected to patenting at a predetermined cooling rate, thereby affording a high-carbon steel wire excellent in workability. It is high-strength steel wire excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 &#x3bc;m and not greater than 45 &#x3bc;m. The invention also provides a high-carbon steel wire excellent in ductility, which is manufactured by subjecting the wire rod to intermediate patenting and cold drawing and has a tensile strength of 2800 MPa or greater.

High-strength wire rod excellent in drawing characteristics and method of manufacturing the same

The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is heated in a specified temperature range to conduct post-reaustenization patenting and thereby obtain a high-carbon steel wire excellent in ductility that has a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and whose fracture reduction of area RA satisfies Expressions (1), (2) and (3) below:RA&#x2267;RAmin&#x2003;&#x2003;(1),

High-strength steel wire excellent in ductility and method of manufacturing the same

A wire rod which is mainly composed of pearlite and has an area fraction of 5% or less of a non-pearlite structure composed of pro-eutectoid ferrite, degenerate-pearlite or bainite in a section, or has an area fraction of 10% or less of a non-pearlite structure in a portion from the surface to a depth of 100 &#x3bc;m.

A plated steel wire for PWS with excellent twist properties contains, in terms of mass %, 0.8 to 1.1% of C, 0.8 to 1.3% of Si, 0.3 to 0.8% of Mn, 0.001 to 0.006% of N, and 0.0004 to 0.0060% of B, where a quantity of solid-solubilized B is at least 0.0002%, also contains either one or both of 0.005 to 0.1% of Al and 0.005 to 0.1% of Ti, and contains as the remainder, Fe and unavoidable impurities, wherein an area fraction of non-pearlite structures in a region from a surface layer down to a depth of 50 &#x3bc;m is not more than 10%, an area fraction of non-pearlite structures within an entire cross-section is not more than 5%, and a surface of the steel wire is galvanized with a plating quantity within a range from 300 to 500 g/m.

Plated steel wire for parallel wire strand (PWS) with excellent twist properties

The present invention provides a high strength, high toughness steel wire rod useful for a PC steel wire, galvanized steel strands, spring use steel wire, cables for suspension bridges, etc. By hot rolling, then directly patenting or reaustenitizing, then patenting a high carbon steel wire rod of a specific chemical composition of the steel and chemical composition, size, and numerical density of inclusions, piano wire rod or high carbon steel wire rod having a structure of mainly pearlite, having an average value of the proeutectoid cementite area ratio of 5% or less in a center region of less than 20% of the wire rod diameter from the center of the wire rod, having a micromartensite size of the C section of 100 &#x3bc;m or less, having a tensile strength of the 170 kgf/mmclass or more, and having a drawing ratio at break of 30% or more is obtained.

High strength, high toughness, high carbon steel wire rod and method of production of same

Plated metal wire and method and apparatus for producing the same

The object of the present invention relates to a plated steel material and a method of production the same, having enhanced corrosion resistance and workability required for outdoor and exposed uses such as structures, revetments, fishing nets, fences, etc., and a method to produce the plated steel material having an alloy layer 20 &mgr;m or less in thickness consisting of, in mass, 25% or less of Fe, 30% or less of Al, 5% or less of Mg and the balance consisting of Zn at the interface of a plated layer and a base steel; also relates to a plated steel material and a method of production the same, excellent in corrosion resistance and workability, having, at the interface of a plated layer and a base steel, an alloy layer composed of: an inner alloy layer 5 &mgr;m or less in thickness consisting of, in mass, 15% or more of Fe, 20% or more of Al, 2% or more of Si, 5% or less of Mg and the balance consisting of Zn; and an outer alloy layer 30 &mgr;m or less in thickness consisting of, in mass, 25% or less of Fe, 30% or less of Al, 2% or more of Si, 5% or less of Mg and the balance consisting of Zn.

Plated steel product having high corrosion resistance and excellent formability and method for production thereof

The present invention relates to a wire rod for high fatigue-strength steel wire of small diameter, and a wire rod used in steel wire obtained by twisting these together, a steel wire and a method of producing the same. The wire rod for steel wire and the steel wire have a microstructure obtained by controlled cooling following hot rolling of a steel, containing, in mass %, 0.6-1.3% of C, 0.1-1.5% of Si and 0.2-1.5% of Mn wherein the area ratio of upper bainite measured in a cross-section thereof is 5-50%, the remainder being substantially composed of pearlite. The production method thereof comprises drawing and patenting a wire rod of 5-16 mm diameter having the aforesaid composition to obtain a wire of 0.8-2.8 mm diameter, then austenitizing the wire, quenching it to a temperature range of 500-560&deg; C. for conducting isothermal transformation, thereby adjusting it to a steel microstructure wherein the area fraction of upper bainite is 5-50%, the remainder being substantially composed of pearlite, and then conducting brass plating and drawing to obtain a wire of 0.05-1.0 mm diameter.

Wire rod for high-fatigue-strength steel wire, steel wire and method of producing the same

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Kimitsu, Japan

Seiki Nishida