公开(公告)号：US20230400298A1

公开(公告)日：2023-12-14

申请号：US18033387

申请日：2021-11-02

Applicant: NIPPON STEEL CORPORATION

Inventor： Tooru AKASHI ,  Keita IKEDA ,  Yasumitsu KONDO ,  Naoki INOUE ,  Akinobu MINAMI

IPC: G01B21/08

CPC classification number: G01B21/085

Abstract: This internal oxide layer thickness estimation device estimates a thickness of an internal oxide layer formed in a hot-rolled steel sheet. The internal oxide layer thickness estimation device includes: a first temperature definition unit that defines a temperature of a portion to be estimated, in which the thickness of the internal oxide layer is to be estimated, in the hot-rolled steel sheet; a second temperature definition unit that defines an internal oxidation starting temperature at which internal oxidation of the hot-rolled steel sheet starts; a cumulative temperature calculation unit that calculates a cumulative temperature on the basis of the temperatures defined by the first temperature definition unit and the second temperature definition unit and a predetermined period of time from an estimation start time at which estimation of the thickness of the internal oxide layer is started to an estimation evaluation time; a first correlation expression derivation unit that derives a first correlation expression indicating a correlation between the cumulative temperature calculated by the cumulative temperature calculation unit and an estimated value of the thickness of the internal oxide layer; and an internal oxide layer thickness estimation unit that estimates the thickness of the internal oxide layer on the basis of the first correlation expression.

公开(公告)号：US20230296579A1

公开(公告)日：2023-09-21

申请号：US18034628

申请日：2021-11-02

Applicant: NIPPON STEEL CORPORATION

Inventor： Keita IKEDA ,  Tooru AKASHI ,  Yasumitsu KONDO

IPC: G01N33/2028 ,  B21B3/02 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02

CPC classification number: G01N33/2028 ,  B21B3/02 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02

Abstract: An internal oxidation starting temperature, estimation device estimates an internal oxidation starting temperature which is a minimum temperature required for an internal oxide layer to grow on a surface of an easily oxidizable element-containing hot-rolled steel sheet including Si, Mn, or Al or any combination thereof. The internal oxidation starting temperature estimation device includes an internal, oxidation starting temperature estimation unit that estimates the internal oxidation starting temperature on the basis of concentrations of the Si, the Mn, and the Al included in the easily oxidizable element-containing hot-rolled steel sheet.

公开(公告)号：US20220347732A1

公开(公告)日：2022-11-03

申请号：US17763877

申请日：2020-10-02

Applicant: NIPPON STEEL CORPORATION

Inventor： Takayuki OTSUKA ,  Tooru AKASHI ,  Kazuki SHIOKAWA ,  Yuki TAKEUCHI ,  Hiroki MATSUBARA

IPC: B21C47/28 ,  B21C47/24 ,  B21B45/02

Abstract: A coil skid on which a hot-rolled coil 1 obtained by coiling a hot-rolled steel sheet is placed includes: at least two or more layers of a metal plate 11 and at least two or more layers of a heat insulating material 12 each stacked alternately, in which the metal plate 11 is in contact with the hot-rolled coil 1. The uneven cooling of an outer peripheral portion of the hot-rolled coil caused by the coil skid is prevented while ensuring the strength of the coil skid, to thereby inhibit the uneven hardness in the longitudinal direction of the hot-rolled coil resulting from this uneven cooling.

公开(公告)号：US20220152679A1

公开(公告)日：2022-05-19

申请号：US17439314

申请日：2020-03-19

Applicant: NIPPON STEEL CORPORATION

Inventor： Tooru AKASHI ,  Seiji ARIZUMI

IPC: B21C47/02 ,  B21C47/28

Abstract: Flatness of a hot-rolled steel sheet in a coil is improved when the hot-rolled steel sheet is wound with a mandrel in a hot-rolling process to manufacture a coil. The mandrel has a protruding shape with a center portion in an axial direction protruding from both end portions when seen from a lateral side in the axial direction. Regarding a peripheral length difference, which is a difference between a peripheral length of the center portion of the mandrel and a peripheral length at a predetermined distance from the center portion, the ratio of the peripheral length difference to the peripheral length of the center portion is preferably 0.0002 to 0.012. The protruding shape may be a trapezoidal shape or a polynomial function shape.