Nippon Steel Corporation

Atsuhiko Yoshie

Takashi Fujita

Seiki Nishida

Akira Takahashi

Satoru Tanaka

Masaaki Fujioka

Satoshi Sugimaru

Kazumi Nishimura

Kazuhiro Kojima

Yasumitsu Onoe

Satoshi Akamatsu

Tadashi Kasuya

Hiroki Miyawaki

Kiyoshi Nishioka

Yuji Nomiyama

Shuji Aihara

Yukihiko Horii

Yokimi Kawashima

Tsukasa Yoshimura

Yoshiyuki Watanbe

Shinichi Shimomura

Masaaki Nagahara

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

This invention provides a plated steel wire with high corrosion resistance and excellent workability, wherein the average composition of the plating alloy in the plated steel wire comprises, in terms of weight percentage, Al: 4-20%, Mg: 0.8-5%, and if necessary one or more from among Si: &lE;2%, Na: 0.001-0.1% and Ti: 0.01-0.1%, with the remainder Zn, and an Fe&mdash;Zn alloy layer of no greater than 20 &mgr;m thickness is present at the plating-base metal interface; it is produced by coating a steel wire with a molten zinc plating composed mainly of zinc as the first stage and then.coating it with a molten zinc alloy plating with the aforementioned average composition as the second stage. The maximum plating bath immersion time is 20 seconds, and the part of the plated steel wire drawn out from the plating bath is purged with nitrogen gas.

Plated steel wire with corrosion resistance and excellent workability, and process for its manufacture

Steel plate less susceptible to welding distortion and highly bendable

A steel plate having a high toughness, low yield ratio and high fatigue strength is provided by preserving the fine metallographical microstructure of martensite or bainite while austenitizing extremely fine portions of the microstructure, and during cooling, dispersing the portions as martensite, retained austenite, cementite or mixture thereof in a tempered martensite or tempered bainite phase.

High toughness low yield ratio, high fatigue strength steel plate and

A steel containing predetermined components is rolled in a recrystallization temperature region or a non-recrystallization temperature region of an austenite and is subsequently subjected to repeated hot bending. Alternatively, a surface layer portion is cooled during rolling of the steel described above to an .alpha. single phase or a .gamma./.alpha. dual phase temperature region, rolling is then effected and is finished at the point of time when the surface temperature of the plate rises above an Ac.sub.3 point due to recuperative heat, and repeated bending is carried out. Still alternatively, the steel described above is rolled to a cumulative reduction ratio of at least 20% in the non-recrystallization temperature region and is then subjected to repeated bending. Further alternatively, the surface layer portion is cooled during hot rolling of the steel described above to an .alpha. single or .gamma./.alpha. dual phase temperature region, rolling is then continued at a cumulative reduction ratio of at least 20% and is finished at the point when the surface temperature of the steel plate rises less than (Ac.sub.3 point--200.degree. C.) due to recuperative heat, and subsequently, repeated bending is carried out.

Production method of strong and tough thick steel plate

Method of estimating properties of steel product

Growing community of inventors

Futtsu, Japan

Atsuhiko Yoshie