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Yamamura H.,Process Technology Center | Yamasaki N.,Plant Engineering and Facility Management Center | Kajitani T.,Technical Development Planning Div. | Mineta S.,Process Technology Center | Nakashima J.,Process Technology Center
Nippon Steel Technical Report | Year: 2013

The heat transfer phenomena in the mold and the strand of continuous casting machine were examined and control technologies were considered. The heat transfer phenomenon through the mold flux film in the mold was examined by the heat transfer measurement experimental apparatus. The cold model experiment that simulate the infiltration of mold flux and the numerical analysis model using the Reynolds equation was developed, and the mechanism of the mold flux infiltration that give the great influence to the heat transfer and the lubrication in the mold was considered. In addition, the mechanism of the hydrogen induced break out was clarified by measurement of the content of OH- radical in mold flux by 1H solid NMR device, and the countermeasures were considered. Furthermore, the FEM model which analyzed the deformation behavior of the solidification shell was developed, and the influence of the mold shape to uniformity of the solidification shell was studied. The numerical analysis model that simulate the behavior of the water in the secondary cooling of strand was developed using a particle method, and the influence of the leak water from the gap between the bearing of sprit roll and the cast slab and the stagnant water in the wedge-shaped space formed by the roll and the slab was examined. Source

Horii K.,Chiyoda Corporation | Tsutsumi N.,Technical Development Planning Div. | Kitano Y.,Plant Engineering and Facility Management Center | Kato T.,Environment Research Laboratory
Nippon Steel Technical Report | Year: 2013

About 40 million tons of steel slag a year, which is the by-product of iron and steel manufacture, is generated in Japan and the almost all the slag is reused for the materials, e.g. cement raw material, road base course material and civil engineering material, by effectively utilizing its characteristics such as chemical components and mechanical properties. Most of its purposes of uses are to replace the functions of the newly mined raw materials from nature and promoting the use of steel slag is an effort to contribute to environmental conservation in this regard. On the other hand, due to the changes in social situation, supply-demand structure in the steel slag market is changing and Nippon Steel Corporation is developing the technologies to create new features of steel slag and to utilize them, especially in the field of Basic Oxigen Furnace (BOF) slag. In this report, the current production and sales status, processing and reusing technologies of BOF steelmaking slag are mentioned. Source

Seto A.,A-D Technologies | Yamamoto T.,Plant Engineering and Facility Management Center | Yoshida Y.,A-D Technologies | Kanoko S.,A-D Technologies
Nippon Steel Technical Report | Year: 2013

Application of high strength steel sheets to automotive bodies requires evaluation technologies of fatigue and noise-and-vibration properties with high accuracy. Automobile partial models were used instead of real bodies for investigation of evaluation methods of those properties. Structural stress concentration parameters gave good estimation of fatigue lives to both of spot-welded and arc-welded models. New analysis methods were proposed for better understanding of vibration phenomena in lowand mid-frequency ranges using bonded models of panel-frame and two panels. Source

Tani M.,Yawata Steel Works | Zeze M.,Yawata Steel Works | Toh T.,Mathematical Science and Technology Research Laboratory | Tsunenari K.,Plant Engineering and Facility Management Center | And 4 more authors.
Nippon Steel Technical Report | Year: 2013

In the electromagnetic casting (EMC) technique, an electromagnetic field is imposed by a solenoidal coil and a Lorentz force is generated at a meniscus. Consequently, a smooth cast surface without defects can be expected. So far concerning with EMC, the billet casting plant test, the slab casting bench scale test on pilot caster and the numerical simulation have been conducted. Finally the slab casting plant tests with the EMC technique were conducted. The castings were very stable and produced without any major difficulties. The qualities of slab cast were greatly improved by the EMC technique. Source

Haga T.,Plant Engineering and Facility Management Center | Katoh K.,Plant Engineering and Facility Management Center | Ibaraki T.,Ironmaking Technical Div.
Nippon Steel Technical Report | Year: 2012

High quality iron ore and coal resources for the steel industry are gradually being depleted. Given this problem, Nippon Steel Corporation has developed technologies to effectively utilize low quality resources. This paper focuses on coal drying methods (DAPS and SCOPE21) that enable the use of large quantities of non- or slightly-caking coals for cokemaking, the selective granulation of limonitic ores, and dust recycling using rotary hearth furnaces (RHF). It also describes the problems encountered during the initial investigation and commercial application of these methods and the measures taken to overcome these problems, as well as outlines some of the future prospects for these technologies. When coal is dried to less than 5% moisture, the pseudo-grains disintegrate, and the fine particles begin to act as individual grains, causing increased dust emissions. It thus became clear that, to suppress coal dust emissions, it was necessary to dry the coal to about 2% moisture so that the pseudo-grains would disintegrate completely; the resulting grains could then be classified by size, and the fine grains could be granulated. Source

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