Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Masafumi Miyazaki

Takeshi Kubota

Hideaki Yamamura

Takashi Morohoshi

Yousuke Kurosaki

Takeaki Wakisaka

Masayuki Hashimura

Takashi Fujita

Takashi Arai

Hideki Oka

Kazumi Mizukami

Kazuto Kawakami

Daisuke Nikkuni

Mamoru Yamada

Naotsugu Yoshida

Kazutoshi Takeda

Takuya Matsumoto

Koji Fujita

Wataru Ohashi

Yoshiaki Natori

Eiichiro Ishimaru

Hiroyoshi Yashiki

Eiichi Takeuchi

Yasushi Kurisu

Naoya Hamada

Yutaka Sadano

Tadahiro Izu

Isao Suichi

Mitsuru Nakayama

Susumu Mukawa

Kazumi Seki

Yasuo Maruki

Hiroshi Harada

Yutaka Matsumoto

Kenichi Yamamoto

Hiroshige Inoue

Takahisa Suzuki

Hideki Hamatani

Takashi Sawai

Yoshihiro Arita

Toshiyuki Shiraishi

Takaaki Fukushi

Tomohiro Konno

Hiroyuki Nakashima

Kazuto Yamamura

Satoshi Akamatsu

Yoshikazu Matsumura

Kenichiro Miyamoto

Hidemaro Takeuchi

Takahide Shimazu

Manabu Eto

Shigenori Tanaka

Akihito Kiyose

Yoshimori Fukuda

Shuichi Inoue

Satoru Mineta

Kazuya Maruyama

Koichi Kirishiki

Junya Yamamoto

Masanobu Hayama

Shuji Wakida

Naoki Kamachi

Masaki Ina

Kazuo Ohnuki

Toshikazu Nishimura

Wataru O-hashi

Ken-ichiro Miyamoto

This manufacturing method for a slab is a method for manufacturing a slab by a continuous casting equipment including a twin-drum type continuous casting apparatus, a cooling apparatus, an in-line mill, and a coiling apparatus. The method includes calculating a friction coefficient from measured values of a rolling load and a forward slip when the slab is rolled, by use of a rolling analysis model, and controlling a lubrication condition during rolling of the slab so that the friction coefficient falls within a predetermined range, wherein, when the friction coefficient is calculated from the measured values of the rolling load and the forward slip by use of an Orowan theory and a deformation resistance model formula based on a Shida's approximate formula as the rolling analysis model, the predetermined range is 0.15 or more and 0.25 or less.

Manufacturing method for slab and continuous casting equipment

A slab casting method using a twin-drum continuous casting device manufactures a slab by solidifying molten metal by a pair of rotating casting drums includes calculating estimated sheet thicknesses on both ends in a width direction of the slab from equation 1 ((estimated sheet thickness)=(cylinder screw down position)+(elastic deformation of casting drum)+(casting drum housing screw down system deformation)+(drum profile of casting drum)−(elastic deformation of casting drum at the time of screw down position zero adjustment)) by using a casting drum housing screw down system deformation characteristic indicating a deformation characteristic of housings that support the casting drums and a deformation characteristic of a screw down system that screws down the casting drums obtained before casting of the slab starts, and controlling screw down positions of cylinders provided on both ends in a width direction of the casting drums.

Slab casting method

A slab manufacturing method in which casting drum housing screw-down system deformation characteristics which have been acquired prior to the start of slab casting and which indicate deformation characteristics of a housing configured to support a casting drum and deformation characteristics of a screw-down system configured to screw down the casting drum is used to calculate an estimated plate thickness at both end portions of a slab in a width direction thereof from Expression 1 ((estimated plate thickness on entry side of rolling mill)=(screw-down position of casting cylinder)+(elastic deformation of casting drum)+(casting drum housing screw-down system deformation)+(drum profile of casting drum)−(elastic deformation of casting drum at time of screw-down position zero-point adjustment)), an entry-side wedge ratio and an exit-side wedge ratio are calculated on the basis of the estimated plate thickness calculated from Expression 1.

Slab manufacturing method and control device

This thin strip manufacture method is a thin strip manufacture method for manufacturing a thin strip by supplying molten steel to a molten steel pool formed by a pair of rotating cooling drums and a pair of side weirs to form and grow a solidified shell on a peripheral surface of the cooling drums, wherein a pressing force P of the pair of the cooling drums is set so that the pressing force P (kgf/mm) of the pair of cooling drums, casting thickness D (mm), and radius R (m) of the cooling drums satisfy 0.90&#x2264;P&#xd7;(D&#xd7;R)&#x2264;1.30.

Thin strip manufacture method

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: 0.0003% or greater and less than 0.0015% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R&#x2212;(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: greater than 0.0100% and not greater than 0.0250% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R=(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

In this cast strip manufacturing method, in a first step, one end side and another end side in a rotation axis direction of a pair of cooling drums are pressed with a first pressure in a direction in which the cooling drums come close to each other, in a second step, the one end side and the another end side in the rotation axis direction of the cooling drums are pressed with a second pressure, which is higher than the first pressure, in the direction in which the cooling drums come close to each other, and in a third step, pressure control is performed so that a total value of reaction forces on the one end side and the another end side in the rotation axis direction of the cooling drums is set to a predetermined value, and rotation axes of the cooling drums are held in parallel.

Cast strip manufacturing method

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: 0.0015% to 0.0100% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R=(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

A side sealing device for a twin-roll continuous casting apparatus, which supplies molten metal to a molten metal pool portion formed by a pair of rotating mold rolls and a pair of side weirs through an immersion nozzle and causes solidified shells to be formed and to grow on peripheral surfaces of the mold rolls to manufacture a cast strip, seals end surface sides of the mold rolls by each side weir. The side sealing device includes a side weir pressing unit that presses the side weir against end surfaces of the mold rolls, and a side weir lifter that pulls the side weir at least upward in a vertical direction.

Side sealing device, twin-roll continuous casting apparatus, and method of manufacturing cast strip

A non-oriented electrical steel sheet according to an aspect of the present invention contains, as a chemical composition, by mass %, C: more than 0% and 0.0050% or less, Si: 3.0% to 4.0%, Mn: 1.2% to 3.3%, P: more than 0% and less than 0.030%, S: more than 0% and 0.0050% or less, sol. Al: more than 0% and 0.0040% or less, N: more than 0% and 0.0040% or less, one or more of La, Ce, Pr, and Nd: 0.0005% to 0.0200% in total, Ca: 0.0005% to 0.0100%, Ti: 0.0005% to 0.0100%, Sn: 0% to 0.10%, Sb: 0% to 0.10%, Mg: 0% to 0.0100%, and a remainder including Fe and impurities, in which Si&#x2212;0.5&#xd7;Mn: 2.0% or more, and Si+0.5&#xd7;Mn: 3.8% or more.

Non-oriented electrical steel sheet

A non-oriented electrical steel sheet contains, as a chemical composition, by mass %, C: more than 0% and 0.0050% or less, Si: 3.0% to 4.0%, Mn: 1.0% to 3.3%, P: more than 0% and less than 0.030%, S: more than 0% and 0.0050% or less, sol. Al: more than 0% and 0.0040% or less, N: more than 0% and 0.0040% or less, O: 0.0110% to 0.0350%, Sn: 0% to 0.050%, Sb: 0% to 0.050%, Ti: more than 0% and 0.0050% or less, and a remainder including Fe and impurities, in which Sn+Sb: 0.050% or less, Si&#x2212;0.5&#xd7;Mn: 2.0% or more, and an O content in a sheet thickness central portion excluding a surface layer portion which is a range from a front surface and a rear surface to a position of 10 &#x3bc;m in a depth direction is less than 0.0100%.

When a Si content (mass %) is set to [Si], an Al content (mass %) is set to [Al], and a Mn content (mass %) is set to [Mn], a parameter Q represented by 'Q=[Si]+2[Al]&#x2212;[Mn]' is 2.00 or more, the total mass of S contained in sulfides or oxysulfides of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, or Cd is 40% or more of the total mass of S contained in a non-oriented electrical steel sheet, a {100} crystal orientation intensity is 3.0 or more, a thickness is 0.15 mm to 0.30 mm, and an average crystal grain diameter is 65 &#x3bc;m to 100 &#x3bc;m.

When a Si content (mass %) is set to [Si], an Al content (mass %) is set to [Al], and a Mn content (mass %) is set to [Mn], a parameter Q represented by 'Q=[Si]+2[Al]&#x2212;[Mn]' is 2.00 or more, the total mass of S contained in sulfides or oxysulfides of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, or Cd is 10% or more of the total mass of S contained in a non-oriented electrical steel sheet, a {100} crystal orientation intensity is 3.0 or more, a thickness is 0.15 mm to 0.30 mm, and an average crystal grain diameter is 65 &#x3bc;m to 100 &#x3bc;m.

A spring steel includes a predetermined chemical composition and a composite inclusion having a maximum diameter of 2 &#x3bc;m or more that TiN is adhered to an inclusion containing REM, O and Al, in which the number of the composite inclusion is 0.004 pieces/mmto 10 pieces/mm, the maximum diameter of the composite inclusion is 40 &#x3bc;m or less, the sum of the number density of an alumina cluster having the maximum diameter of 10 &#x3bc;m or more, MnS having the maximum diameter of 10 &#x3bc;m or more and TiN having the maximum diameter of 1 &#x3bc;m to 10 pieces/mm.

Spring steel with excellent fatigue resistance and method of manufacturing the same

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Tokyo, Japan

Masafumi Miyazaki