Nkk Corporation

Masahisa Fujikake

Yuji Yamasaki

Reiko Sugihara

Yoshinori Yomura

Kazutaka Kobayashi

Masayoshi Kurihara

Jun Furukawa

Yoichiro Yamanaka

Kozo Fukuda

Yutaka Mihara

Hideyuki Yamanaka

Shinichi Nagahashi

Kiyotaka Morioka

Sadahiro Yamamoto

A method for making an easy-opening can end comprising providing an upper die and a lower die, at least one of the upper die and the lower die having a curved surface with a radius of 0.1 to 1 mm at the tip portion thereof, the other die having a flat surface at the tip portion thereof; and press-forming an end panel by using the upper die and the lower die to form a score on the upper surface or the lower surface of the end panel so that the end panel has a thickness of 0.025 to 0.08 mm at the thinnest portion thereof.

Methods for making an easy-opening can end

An easy opening can end is provided whose can end panel is made of steel sheet having both sides coated with resin layers which each include at least one type of thermoplastic resin and which have elongation after break of 100% or more, tensile strength of 10 kg/mm or more, Young modulus of 100 kg/mm or more and a thickness in range of 10 to 100 &mgr;m. A score is formed on at least one of a front or a back side of the can end panel so as to be capable of breakage for opening the can end. The score has a bottom cross-section in a shape of an arc having a radius in a range of 0.10 to 1.0 mm, and a thinnest section of the score has a thickness t in a range of 0.025 to 0.080 mm. The easy opening can end has no problem of resin layer damage when the score is formed and has excellent can openability to such an extent that children and the aged may easily open the can end, so that the easy opening can end is most suitable for a can end of a beverage can and a food can.

Easy opening can end and method for fabricating the same

A high-strength, high damage-resistant rail made of 0.6 to 0.85 wt % C, 0.1 to 1.0 wt % Si, 0.5 to 1.5 wt % Mn, 0.035 wt % or less P, 0.040 wt % or less S, and 0.05 wt % or less Al, with the balance being Fe and inevitable impurities, and having corner and head side portions having a Brinell hardness of 341 to 405, and a head top portion in which a Brinell hardness of a site 20-mm distant from the central portion of the head top portion in a width direction is 341 to 405, and a hardness of the central portion of the head top portion is at least 10 lower in Brinell hardness than that of the site 20-mm distant from the central portion.

High-strength, damage-resistant rail having hardness distribution of excellent damage-resistance at its head top portion

A high-strength bainitic steel rail having an excellent damage resistance property, essentially consists of 0.2 to 0.5 wt % of C, 0.1 to 2.0 wt % of Si, 0.3 to 4.0 wt % of Mn, 0.035 wt % or less of P, 0.035 wt % of S, and 0.3 to 4.0 wt % of Cr, a balance being Fe, and having a micro structure made of a bainitic structure. This rail includes corner and head side portions having a Vickers hardness of Hv420 or higher, and a head top portion having a hardness of Hv420 or higher at a site 20-mm distant from a center of the head top portion in a width direction, wherein the center of the head top portion has such a hardness distribution that a hardness of the center of the head top portion is 10 to 70 lower in Vickers hardness than that of the site 20-mm distant from the center of the head top portion, a hardness of a section between the center of the head top portion and the site 20-mm away from the center in the width direction increases gradually from the center towards an outer side of the width direction, and a difference between an actual hardness of the section, and a hardness obtained by interpolating the hardness of the center of the head top portion and the hardness of the site 20-mm away from the center in the width direction by straight line, is 10 or less in Vickers hardness.

High-strength, bainitic steel rail having excellent damage-resistance

Growing community of inventors

Fukuyama, Japan

Masahisa Fujikake