Jfe Steel Corporation

Nkk Corporation

Other

Toyota Jidosha Kabushiki Kaisha

Toru Minote

Yoshimichi Hino

Yoichi Motoyashiki

Akio Fujibayashi

Sadanori Imada

Shozo Ikemune

Masaaki Yamamoto

Yoshikiyo Tamai

Sadakazu Masuda

Yuichi Tokita

Takumasa Terauchi

Tatsuya Nakagaito

Hisatomo Eda

Takeshi Fujita

Kazuyuki Sato

Yasuhiro Fujii

Satoshi Murata

Nobuhiro Tazoe

Masaki Urabe

Hisashi Honjou

Kenichi Ide

Hideaki Kobiki

Hiroshi Sekine

Shigeki Narushima

Yasushi Dodo

Shinji Okazaki

Hajime Ishii

Shuichi Yamashina

Kinichi Higuchi

Masaki Morino

Masaru Miyake

Shozo Azuma

A method for manufacturing a hot press formed part, includes: preparing a hot press forming object comprising a single-ply portion and a two-ply portion; heating the hot press forming object to a temperature range from an Actransformation temperature of a base steel sheet of the first coated steel sheet to 1000&#xb0; C.; press forming the hot press forming object to obtain a formed body, the press forming being started upon temperatures of the single-ply portion and of the two-ply portion being no higher than solidification points of Zn&#x2014;Ni coating layers of the first and second coated steel sheets and no lower than an Artransformation temperature of the base steel sheet of the first coated steel sheet; and quenching the formed body to thereby obtain a hot press formed part, in which the hot press forming object has a thickness ratio from 1.4 to 5.0.

Method for manufacturing hot press formed part and hot press formed part

A method of manufacturing a hot press formed part by hot pressing a coated steel sheet that is obtained by forming a Zn-based coating layer on a surface of a steel sheet includes: heating the coated steel sheet to a temperature range of 750&#xb0; C. or more and 1000&#xb0; C. or less; cooling a surface of the coated steel sheet; and hot press forming the coated steel sheet under a condition that a surface temperature of the coated steel sheet is 400&#xb0; C. or less and an average temperature of the coated steel sheet is 500&#xb0; C. or more or a temperature of a center position of the coated steel sheet in a thickness direction is 530&#xb0; C. or more.

Method of manufacturing hot press formed part, and hot press formed part

A method of analyzing press-forming of a press-forming material including analyzing press-forming, analyzing springback and analyzing a change in shape of the press-forming material. The analyzing press-forming may include setting an initial temperature distribution for the heated press-forming material and performing a press-forming analysis by combining temperature analysis and structural analysis to obtain shape information, temperature distribution, stress distribution, and strain distribution. The analyzing springback may occur with and without consideration of contact heat transfer between a press-forming tool and the press-forming material. The method may further include modifying the temperature distribution obtained in the analyzing springback and then re-analyzing the change in shape of the press-forming material. The analyzing the change in shape may be performed until a temperature distribution in the press-forming material is within the range of &#xb1;5&#xb0; C.

Method of analyzing press forming

A method for cooling a hot rolled steel strip including transferring a hot rolled steel strip while ejecting cooling water from a cooling means at a specified ejecting condition; pinching a top end of the hot rolled steel strip by a pinching roll, at the inlet of the cooling means and/or just behind the cooling means and/or at a position on the way of the cooling means; and releasing the hot rolled steel strip sequentially from a pinch roll arranged at an upstream side, concurrently with the arrival of a top end of the steel strip to a tension adding means arranged at a downstream side.

Method for cooling hot roller steel strip, and method for manufacturing hot rolled steel strip

An apparatus for cooling a hot rolled steel strip including a transfer means comprising transfer rolls to feed a steel strip which has been hot rolled by a finishing mill; a cooling means for cooling the steel strip; and accompanying rolls arranged with a clearance over the thickness of the steel strip at a position where the accompanying rolls face the transfer rolls through the steel strip to be transferred. The accompanying rolls rotate at nearly an equal peripheral speed as the transfer rolls or at a peripheral speed greater than the transfer speed of the steel strip.

Method and apparatus for cooling hot rolled steel strip, and method for manufacturing hot rolled steel strip

An apparatus for cooling a hot rolled steel strip comprising a transfer means arranged behind a final finishing mill, the transfer means comprising a plurality of transfer rolls for transferring the steel strip; at least one upper surface cooling means arranged at an upper surface side of the transfer means for cooling the steel strip by ejecting cooling water to an upper surface of the steel strip, the upper surface cooling means being capable of moving freely up and down and having a water breaking means at least at an outlet side of the cooling apparatus and at a position corresponding to the transfer rolls; and at least one lower surface cooling means arranged at a lower surface side of the transfer means relative to the upper surface cooling means and the steel strip to be transferred, for cooling the hot strip by ejecting cooling water at a lower surface of the steel strip.

A lower surface cooling box is arranged between transfer rolls on a runout table and an upper cooling box moving freely is arranged at a position corresponding to the cooling box to eject cooling water to the steel strip symmetrically in the vertical direction. The steel strip passes the center of converge of cooling water from upper and lower surfaces of the steel strip. A water breaking roll is provided elevating freely at least at the outlet side rotating at the same peripheral speed as the transfer rolls and is rotated to lower concurrently with passing of the steel strip top at the cooling apparatus. The upper cooling box is also lowered concurrently to cool the steel strip.

A high-quality hot rolled steel sheet is manufactured with a high production efficiency and a low cost, from a long, hot slab, using a combination of continuous casting facilities and a plate reduction press machine.

Apparatus and methods for manufacturing hot rolled steel sheets

A method and hot rolling apparatus for producing a hot rolled steel sheet include a roughing rolling mill to roughing roll a heated slab into a sheet bar, at least one solenoid-type induction heater arranged for re-heating the sheet bar over its entire width, and a finish rolling mill arranged to finish roll the re-heated sheet bar into a hot rolled steel sheet having a predetermined thickness. An initial temperature before rolling is set to be low, and re-heating of the sheet bar is carried out around the middle of the hot rolling apparatus. The thermal energy required for rolling is thereby reduced as a whole without damaging the quality of the resulting hot rolled steel sheet. A descaling apparatus is provided prior to the finish rolling mill to remove oxide scales on surfaces of the sheet bar, whereby the resulting hot rolled steel sheet is free of scale flaws and exhibits superior surface properties.

Method for producing hot rolled steel sheet using induction heating and

Making method of hot-rolled steel sheet comprises rough rolling a slab into a rough bar, heating the rough bar, guiding the rough bar with side guides and finish rolling the rough bar. The apparatus comprises a rough rolling mill, a heating device for heating the rough bar, side guides for guiding the rough bar and a finish rolling mill.

Method for making hot-rolled steel sheet and apparatus therefor

Growing community of inventors

Tokyo, Japan

Toru Minote