Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Masahiro Doki

Ryuji Yamamoto

Shigeru Ogawa

Yoshihiro Serizawa

Yasuhiro Nishiyama

Hironori Ueno

Junichi Nakagawa

Tadayuki Ito

Masahiro Yamamoto

Takeshi Kawachi

Kozo Saito

Kazuto Yamamura

Tetsuo Nishiyama

Hiroyuki Mitake

Shigenori Tanaka

Mitsuo Uchimura

Katsushige Matsuzaki

Hiroki Miyawaki

Yoshiaki Kimura

Junichi Kinoshita

Huaxiong Huang

Teruo Kawabata

Masanao Yamamoto

Ahmad Salaimeh

Keng Hoo Chuah

Belal Gharaibeh

Masato Sanazawa

Tomoya Takeuchi

Katsuhiro Imanaga

Hiroshi Ohba

Jun Fukuda

Toyoichiro Higashi

Sean C Bohun

Kazufumi Ito

A defect on the surface or in the surface layer of a moving material can be detected by using a method comprising steps of: heating the surface of the material, obtaining thermal image data of the surface of the material using an infrared thermography camera while the surface of the material is being heated up at the heating step or being cooled down after heating, and detecting the defect by calculating Laplacian with respect to temperature of the surface represented by the thermal image data. When the thermal image data is obtained while the material is being heated up, a heating device and the camera is arranged so that thermal energy emitted from the heating device is reflected by the material to come into the camera.

Method for detecting defect in material and system for the method

The present invention relates to a method of arranging and setting spray nozzles in a cooling apparatus comprising a plurality of pairs of constraining rolls for constraining and conveying a hot steel plate and one or more lines of spray nozzles between the pair of constraining rolls, each line having a plurality of spray nozzles and is disposed in a direction perpendicular to processing, and to the cooling apparatus and the method of cooling. The invention is characterized in that the spray nozzles are arranged such that a distribution of values &#x222b;Pbetween two edges of the steel plate in the direction perpendicular to processing is not less than 80% of its highest value, with P being cooling water impact pressure on the cooling surface, &#x222b;Pbeing the value of n power of P integrated in the processing direction between the pairs of constraining rolls, and 0.05&#x2266;n&#x2266;0.2.

Method of arranging and setting spray cooling nozzles and hot steel plate cooling apparatus

The present invention relates to an apparatus for cooling a hot steel plate which is processed and constrained by constraining rolls and a method of arranging and setting spray nozzles enabling uniform cooling in a direction perpendicular to processing. In the apparatus and method of the invention, the spray nozzles are arranged so that a value of n power of the impact pressure of the cooling water on the cooling surface integrated in the processing direction between pairs of constraining rolls becomes within &#x2212;20% of the highest value in the direction perpendicular to processing, where 0.05&#x2266;n&#x2266;0.2.

An apparatus for controlled cooling of hot steel plate while constraining and conveying the plate by constraining rolls horizontally which is inexpensive and enabling continuous control of the cooling ability over a broad range, that is, a cooling apparatus for spraying hot steel plate hot rolled and transferred between pairs of constraining rolls with cooling water from pluralities of lines of spray nozzles so as to cool the same, which apparatus has lines of gentle cooling spray nozzles and lines of strong cooling spray nozzles with different orifice shapes and enables continuous control of the cooling ability over a broad range due to the fact that a maximum cooling water impact pressure integrated value of the lines of gentle cooling spray nozzles and a minimum cooling water impact pressure integrated value of the lines of strong cooling spray nozzles are continuous.

Cooling apparatus of hot steel plate, cooling method of hot steel plate, and program

A billet produced by continuous casting having little central segregation, in particular a billet of high carbon steel produced by continuous casting, and a manufacturing method therefor are provided. In the continuous casting billet, the size of the dendritic equiaxed crystal in a billet central portion is reduced to be not more than 6 mm. For this purpose, electromagnetic stirring is performed so that the inclining angle of the primary dendrite within 10 mm of a billet surface layer is increased to be not less than 10&#xb0;. Furthermore, the mechanical soft reduction is performed during continuous casting so that the diameter of the center porosity in the billet central portion is reduced to be not more than 4 mm. Thereby, in particular in the manufacturing of the continuous casting billet having a carbon content of not less than 0.6% by mass and a billet size of not more than 160 mm can be provided a billet in which breaking troubles in wire drawing after rolling to a rod are reduced by reducing the central segregation in the billet.

Billet by continuous casting and manufacturing method for the same

A transferred plasma heating anode for heating a molten metal in a container by applying Ar plasma generated by passing a direct current through the molten metal, the transferred plasma heating anode comprising; an anode, composed of a conductive metal, that has an internal cooling structure, a metal protector having an internal cooling structure that is placed outside the anode with a constant gap between the anode and the protector, and a gas supply means that supplies an Ar-containing gas to the gap, is characterized by the central portion on the external surface of the anode tip end being inwardly recessed.

Transfer type plasma heating anode

Hot steel plate as hot-rolled is passed forward longitudinally through pairs of top and bottom rollers disposed in the direction of the plate travel. The steel plate is cooled with water supplied to its top and bottom surfaces from the nozzles on a plurality of cooling units disposed in the same longitudinal direction. Each cooling unit is disposed between adjoining pairs of the top and bottom rollers. Before cooling is started, the temperature distribution in the steel plate is determined and the desired mean cooling rate is set. The distance from the plate edge over which the supply of the cooling water at least to the bottom side of the plate is to be cut off is determined for each cooling unit on the basis of the determined temperature distribution and preset mean cooling rate. By so doing, the temperature of the inner edge portion of the steel plate is kept above the temperature of the middle portion, thereby allowing the Ar.sub.3 transformation in the inner edge portion to occur simultaneously with or after the Ar.sub.3 transformation in the middle portion. The cooling water directly supplied to the edge portion of the steel plate is cut off over the distance thus determined.

Method of cooling hot steel plates

Growing community of inventors

Tokyo, Japan

Masahiro Doki