Kawasaki Steel Corporation

Jfe Steel Corporation

Makoto Aratani

Hideo Kuguminato

Akio Tosaka

Susumu Okada

Masatoshi Aratani

Katsumi Kojima

Hiroki Iwasa

Takumi Tanaka

Osamu Furukimi

Masaki Tada

Hiroki Nakamaru

Kaneharu Okuda

Yuji Miki

Reiko Sugihara

Tetsuya Fujii

Kenichi Sorimachi

Shuji Takeuchi

Saburo Moriwaki

Hajime Takada

Hirokazu Tozawa

Tomonari Hiraguchi

Masuto Shimizu

Noboru Yasukawa

Toshihiro Kikuchi

Yoshiro Tomiyama

Masato Iri

Hidenori Miyake

Takeshi Shiraishi

Yasuo Tomura

Mitsuru Sakurai

Toshihiro Sasaki

Yukio Kobata

Naotoshi Ryu

Fumio Aoki

Masami Tsujimoto

A method of manufacturing a high-strength steel sheet includes, on a mass percent basis, 0.03%-0.10% C, 0.01%-0.5% Si, 0.001%-0.100% P, 0.001%-0.020% S, 0.01%-0.10% Al, 0.005%-0.012% N, the balance being Fe and incidental impurities, and microstructures that do not contain a pearlite microstructure, wherein, when Mnf=Mn [% by mass]&#x2212;1.71&#xd7;S [% by mass], Mnf is 0.3 to 0.6, including: forming a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is 800&#xb0; C. or lower, or 900&#xb0; C. or higher; forming a steel sheet by hot-rolling the slab followed by cold rolling; annealing the steel sheet after the cold rolling; and skinpass rolling at a draft of 3% or less after the annealing.

Method of manufacturing high-strength steel sheet for a can

A method provides a slab by continuous casting of a steel having a component composition of, in mass %, C: 0.005% or less, Mn: 0.05 to 0.5%, Al: 0.01 to 0.10%, N: 0.0010 to 0.0070%, B: 0.15&#xd7;N to 0.75&#xd7;N (0.15 to 0.75 in terms of B/N), and one or both of Nb: 4&#xd7;C to 20&#xd7;C (4 to 20 in terms of Nb/C) and Ti: 2&#xd7;C to l0&#xd7;C (2 to 10 in terms of Ti/C), and the balance of Fe and inevitable impurity elements; rough rolling the slab; finish rolling the rough-rolled slab wherein 5% or more and less than 50% of the total amount of rolling reduction in the finish rolling is hot-rolled at a temperature lower than the Artransformation point; winding the hot-rolled steel sheet at a winding temperature of 640 to 750 &#xb0; C.; pickling the coiled steel sheet; cold rolling the pickled steel sheet at a rolling reduction rate of 88 to 96%; and annealing the cold-rolled steel sheet in a temperature range of higher than 400 &#xb0; C. to a temperature that is 20 &#xb0; C. lower than the recrystallization temperature.

Manufacturing method of steel sheet for cans

A flaw detecting method and apparatus for continuously testing a strip that is continuously carried through a liquid includes features for reducing air bubble generation in a liquid. The apparatus includes a liquid, carrying rolls for passage of the strip through the liquid, and ultrasonic testing probes arranged in the liquid for testing the strip. A carrying roll in contact with the liquid is fully immersed. Air bubble generation is inhibited to improve the testing reliability by at least one of (a) shielding the liquid dropping from the portion of the strip leaving the liquid, (b) reducing the dropping force of the liquid onto the liquid surface by inclining the strip, (c) installing the fully immersed carrying roll at a depth of at least 5 mm in the liquid, and (d) using a carrying speed of less than about 200 m/min. Upon manufacturing steel strips, testing is carried out in the stage of hot-rolled steel sheet, or, preferably, in pickling equipment.

Method and apparatus for detecting flaws in strip, method of manufacturing cold-rolled steel sheet and pickling equipment for hot-rolled steel strip

The invention provides a can steel sheet having satisfactory surface appearance and having workability, appearance property after working and high yield that can meet demands on complicated can forming, and a manufacturing process thereof. To be more specific, according to the invention, a slab having a composition containing, in weight %, C: more than 0.005% and equal to or less than 0.1%, Mn: 0.05-1.0% is subjected to hot-rolling at a finishing temperature of 800 to 1000&deg; C., to coiling at 500 to 750&deg; C., to cold-rolling, followed by continuous annealing at a recrystallization temperature or higher and 800&deg; C. or lower, and then to box annealing at a temperature higher than 500&deg; C. and equal to or lower than 600&deg; C. for 1 hr or longer. The steel sheet has preferably a structure containing ferrite as a principle phase and having a mean grain diameter of 10 &mgr;m or less and further containing 0.1-1% by weight of pearlite grains each having a grain diameter of 0.5-3 &mgr;m. To obtain satisfactory surface appearance, it is preferable that the steel contains: Ti: 0.015-0.10%, Al: 0.001-0.01%, and a total of 0.0005-0.01% of one or two members of Ca, REM, and S&minus;5&times;((32/40)Ca&plus;(32/140)REM) of 0.0014% or less.

Steel sheet for can and manufacturing method thereof

At least both ends of a sheet bar in the length direction, which is obtained by roughly rolling a steel slab including 0.1 wt % or less of C, 0.5 wt % or less of Si, 1.0 wt % or less of Mn, 0.1 wt % or less of P, 0.05 wt % or less of S, 0.20 wt % or less of Al, and 0.015 wt % or less of N, are heated so that the temperature at both ends of the sheet bar in the length direction is 15&deg; C. or more higher than the temperature of the remainder of the sheet bar. The rolling finish temperature is Ar,&plus;20&deg; C. to Ar,&plus;100&deg; C. in both end portions of the sheet bar in the length direction, and Ar,&plus;10&deg; C. to Ar,&plus;60&deg; C. in the remainder, and the rolling finish temperature in the both end portions in the length direction is 10&deg; C. or more higher than that of the remainder, so that a steel strip after cold rolling and annealing has r values within &plusmn;0.3 of the average r value, and &Dgr;r within &plusmn;0.2 of the average &Dgr;r in the region of 95% or more of each of the total length and total width of the steel strip.

Method of producing can steel strip

Extremely-thin steel sheets and method of producing the same

One or more streams of molten metal poured into a continuous casting mold are acted on magnetically by static magnetic fields, covering substantially the entire width of the casting mold, thereby reducing the speed of the molten metal streams from the immersion nozzle, unifying the flow profile of the molten metal in the mold, preventing trapping and accumulating of mold powders and inclusions into the cast products. Magnetic poles are provided which are at least as wide as or wider than the minimum width of the cast products and the iron core is arranged on the same face of the casting mold with mutually opposite polarities in the drawing direction. Even if casting conditions change from time to time, defects in final products made of the cast metal are substantially reduced.

Apparatus and method for continuous casting

Growing community of inventors

Chiba, Japan

Makoto Aratani