Vol.50, No.3 / Dec. 2000


SUMMARY

6	Blast Furnace High Pulverized Coal Rate Injection at Kobe Steel
		Ryoji Ito/Yasuo Yoshida/Koichi Hoshino/Fumio Noma/Dr. Tomio Suzuki
		The theory and methods required to achieve high PC rates injection in blast furnaces are described. The paper begins with historical developments of burden distribution control with center coke charging to achieve stable cohesive zone shaping, and then discusses double-lance raceway combustion techniques for complex blasts combining coal and oxygen. Following these techniques improved furnace performance for start-up coal injection after blow-in is shown to be progressive and highly advantageous. The paper ends with a discussion of the future of blast furnace technology.

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12	Developments of High-repetition Tundish Operation under Hot Conditions in Continuous Casters
		Masayasu Kimura/Shinichi Nakajima/Hikaru Ueta/Masaru Nakao
		Small lot production in continuous casters is expensive and yields poor quality steel. To prevent this, highrepetition tundish operation under hot conditions was developed for the first time in the world at Kobe Steel's Kakogawa Works in 1989. In this process, reduction of FeO and MnO in tundish is achieved by repeated tundish operation without pre-heating on slag conditioning. High-repetition tundish operation reduces inclusions in the slab and produce defect-free clean steel.

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16	Developments in Structural Steel Plates for High-heat Input Welding
		Manabu Yamauchi
		New steel plates for high-heat input welding were developed by utilizing TiN dispersion technology (KST treatment) and a thermomechanical control process (KCL process) . New steels make high efficiency welding in the construction of ships, buildings and bridges possible. This paper describes recent developments in steel plates for high-heat input welding including the use of microalloys and advanced steel plate manufacturing.

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20	Developments and Trends related to High-strength Steel Sheet for Automotive Use
		Yoshinobu Omiya
		In 1984, Kobe Steel developed and began selling highly ductile 980MPa grade cold rolled steel characterized by a transformed microstructure. Recently, by applying the knowledge and technology obtained by producing this steel, advanced high-strength steels--such as Dual-phase hot dip galvannealed steel ; hot and cold rolled steel including retained austenite ; and excellent stretch flangeability hot rolled steel--have been developed. Over the past few years and increasingly now, the demand for such steels has risen dramatically in the auto industry to reduce car body weight.

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24	Developments in Special Film Coating Steel Sheet
		Tadashige Nakamoto/Atsushi Kihara/Tomio Kajita
		Recently, the household electrical appliance field has undergone great changes. Today, the manufacturers of such appliances are demanding steel sheet having several special characteristic. Special film coated steel sheet is one kind of steel that is now widely called for and in demand in this industry. Kobe Steel has developed several kinds of special film coating steel sheets which have excellent performance characteristics and have proven to be highly popular with appliance manufacturers.

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27	Developments in Automotive Valve Spring Wire Rods
		Nobuhiko Ibaraki
		To increase engine power and reduce fuel consumption, automotive valve spring weight reduction is of great importance. Automotive manufacturers have requested wire rod mills to develop high-fatigue, high-strength, super-clean valve spring wire rods, without surface defects, in order to greatly reduce valve spring weight. This paper describes the development history of high-fatigue, high-strength valve spring wire rods. Special attention is given to technology related to the control of non-metallic inclusions and surface quality assurance.

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31	Developments in Steel Cord Wire Rods
		Takaaki Minamida/Noriaki Hiraga/Takao Shibata
		Over the past 50 years, steel cord wire technology has progressed steadily. To meet stringent customer requirements, Kobe Steel developed inclusion control and wire rods design for high tensile situations. Such innovations have resulted in a significant reduction in tire weight. This report describes developments in steel cord wire rod technology, focusing especially on aspects related to inclusion control and high tensile strength.

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36	Developments Related to Atomized Steel Powders
		Kenji Kawai/Yoshikazu Seki/Minoru Takada/Hitoshi Sakuma/Masahiro Murakami/ Shinya Kawai
		Kobe Steel has been producing atomized steel powder since 1970, and has made great efforts to increase overall production capacity and develop new type of steel powders to meet the ever increasing demand for P/M parts related to recent developments in the automobile industry. In 1989, Kobe Steel successfully began operating an advanced steel powder plant in Seymour, Indiana (USA) to meet American automobile industry demand for steel powder products. This paper describes developments in Kobe Steel's related production technologies and R&D, as well introducing specifies concerning the properties of atomized steel powders.

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41	Evolution of the Kobe Steel Cast Steel Build-up Type Crankshaft
		Dr. Hiroyuki Mori/Dr. Tomohiro Tsuchiyama/Eiichi Oku/Haruyoshi Kubo/ Kiyoyuki Ijima/Atsuhito Yoshimoto
		Kobe Steel has developed and manufactured build-up type crankshafts made of cast steel since 1955. In order to meet customer demand for increased crankshaft output and compactness, Kobe Steel has continued to develop and improve this type of crankshaft. This paper describes the development history and present activities (casting design, steel-making process, cast steel material and fillet cold rolling) related to these types of crankshaft.

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46	Developments in Titanium and Titanium Alloy Strip Rolling Technology
		Masahito Fukuda
		The historical development of titanium strip rolling technology in hot steel rolling mills is described, and reverse cold mill and annealing and pickling equipment historical development is also introduced. A number of unique titanium and titanium alloy products that have been manufactured with this process and equipment are also presented.

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50	Past and Future Developments of Aluminum Substrates for High Density Magnetic Disks
		Yoshinori Kato/Hidetoshi Umeda/Hideo Fujimoto
		KOBELCO's aluminum substrate products, which currently command more than 50% market of the global market, are widely used in high-density, advanced magnetic disks. High-quality magnetic disks demand optimal alloys, the critical control of intermetallic compounds morphologies, and a highly sophisticated level of production technology. Though future alternative substrate development for advanced hard disk drives (HDD) is currently being researched worldwide, cost-effective aluminum substrates, which are widely available, will continue to dominate this fast-growing, important market.

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54	Technical Innovations in Aluminum Beverage Can Stock
		Takashi Inaba
		This paper deals with the history of beverage can technologies. Aluminum cans are produced at the Mooka Plant, which is part of Kobe Steel Limited's (KSL) aluminum division. In 1993, the production and sale sides of this business was transferred from KSL to KAAL, a joint venture between KSL and ALCOA. KS3004-H191 and KS5K52-H19 aluminum alloys are typical of the new can stock developed by KSL. Can technologies for KAAL are developed jointly by KSL and ALCOA. The future beverage can business is expected to expand and grow from the development of resealable aluminum bottles and an increased can recycling ratio.

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58	Trends in Aircraft Sand Casting at Kobe Steel
		Mamoru Nakata/Susumu Koike
		Since 1937, Kobe Steel has enjoyed critical acclaim from Japanese aircraft manufacturers, and has maintained the top market share for its aluminum/magnesium castings. Kobe Steel uses two techniques for such castings : a Zr-magnesium alloy casting technique, and a low-pressure casting technique. The production of magnesium alloy casting WE43, a Mg-Y-R.E.-Zr system alloy, requires Cl-free melting and the inert gas shielded casting. A casting process for D357-T6, a high-strength aluminum casting alloy for large integrated aircraft structures, is currently being developed.

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62	KFC® Copper Alloys for IT-related Electronic and Electric Devices
		Motohisa Miyafuji
		KFC(Cu-0.1%Fe-0.03�%P) is the leading alloy used in semiconductor lead frames, terminals and connectors worldwide. Strengthening of KFC depends on Fe2P precipitates. KFC-type alloys, such as KLF-5, KLF5Z, KLF-7, and CAC16, are currently in wide use as connector and busbar material in the automotive industry. This paper describes the important characteristics and developments related to KFC, and the leading KFC-type alloys.

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66	Inner Grooved Copper Tubes Development
		Akio Isozaki/Mamoru Ishikawa/Chikara Saeki
		Freezers and air conditioners play an essential role in our daily life. Kobe Steel has long been a leading supplier and innovation expert for various types of high-performance heat exchanger tubes for such appliances. Over the past twenty years, inner grooved copper tubes have been successfully used in air conditioners to reduce energy consumption and to improve overall performance. This paper introduces historical developments in inner grooved copper tubes over the past twenty years, and how such developments have been in response to changing market demands.

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70	One-side Submerged Arc Welding : the Key to Modern Ship Construction
		Kaoru Nagatani/Masaharu Komura
		The Japanese ship building industry has long been a world leader for new developments and unique ship building technologies, such as large scale hull block construction and the use of pre-welded longitudinal panels. While reviewing developments in one-side submerged arc welding, a key technology, this paper discusses changes in welding material composition in response to advances in modern steel alloys used in the shipping industry.

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74	Past and Present Developments in Flux-cored Wire for MAG Welding
		Tsuyoshi Kurokawa
		Flux-cored wire use for MAG welding has increased dramatically over the past 20 years in Japan. Domestic production reached 84 000 tons in 1999, which was approximately 30�% of the total production of arc welding materials. Flux-cored wire continues to be dominant in the shipbuilding industry. However, due to its excellent cost effectiveness, use has expanded greatly in other industries. This paper outlines developments in the production and expanded use of flux-cored wire for mild and 490N/mm2 class high tensile steels.

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78	Waste Melting Technologies for Environmental Preservation and Recycling
		Dr. Yasuo Higashi/Takeo Yoshigae/Toshio Kasai/Dr. Tomio Suzuki/ Shigeyoshi Tagashira/Yoshiaki Shimizu
		Kobe Steel developed a swirl-flow melting technique for sewage sludge and, based on this technique, delivered a 40ton cake/day plant in 1990, and a large-scale 120ton cake/day plant in 1996. Kobe Steel has also developed a plasma melting technique for municipal solid waste incineration fly ash ; the first 5ton ash/day plant based on this technique was built in 1997. Both of these melting technologies are considered to be effective solutions for reducing the load on landfill sites and transforming harmful materials into harmless, and stable matter. The usefulness of both of these systems was confirmed through active and long-term commercial plant operation.

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82	Cable Manufacture and Erection of Suspension Bridges
		Dr. Kenichi Sugii
		Kobe Steel has been manufacturing suspension bridge cables, and developing innovative bridge cable erection techniques since 1955. Kobe Steel engineers and products were involved in nearly every suspension bridge built in Japan. This paper describes Kobe Steel's past, present and future suspension bridge cable and erection developments and projects.

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86	Improvements in the MIDREX® Direct Reduction Process
		Yutaka Inada
		The MIDREX Direct Reduction Process was developed during the 1960s. The process, consisting of shaft furnace and stoichiometric gas reforming system, reduces iron ore into direct reduced iron with utilizing natural gas. The first module was built in 1969. Since then 49 additional modules have been built and achieved 67�% share in this field. Over the years, numerous technical improvements have been made, including larger shaft furnaces, hot briquetting, better catalysts, and greater heat recovery. KSL and MIDREX are constantly developing this technology to improve economy-of-scale, to apply alternate fuels, and to realize direct reduced iron hot charging, etc.

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90	Past and Future Developments in Air Separation Units at KOBELCO
		Shinichi Miura/Satoshi Morimoto/Kazuhiko Asahara
		Kobe Steel developed its first air separation unit in 1934. Since then, more than 350 air separation and gas separation units have been developed. Over the past 66 years, numerous new technologies have been developed in relation to air separation units, such as screw and turbo compressors, ALEX, He refrigerators, and LNG facilities. This paper introduces the past and present developments in air separation units at Kobe Steel.

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95	Big Strides to a World Leading Heavy Wall Pressure Vessel Manufacturer
		Shiro Nose/Masato Yamada/Toshiaki Fukada/Dr. Tadamichi Sakai/ Dr. Masayoshi Kohno/Akinobu Goto
		In the 1970s, Kobe Steel lagged behind the competition in the heavy wall reactor manufacturing field, due to insufficient facilities and knowledge. However, as a result of sustained and highly successful efforts over the past two decades, Kobe Steel became the world's leading manufacturer of heavy wall reactors for oil refineries in late 1990s. Today, Kobe Steel is the only company in the world capable of producing everything required for the manufacture of heavy wall reactors, including the base metals and welding materials. This paper discusses the company's past achievement and its future plans in this area.

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99	Past and Present Developments in Screw Compressors at Kobe Steel
		Takao Ohama/Noboru Tsuboi/Kazuo Kubo
		Kobe Steel manufactured the first Japanese screw compressor in 1955. Since that time, the company has continued to develop this technology and its applicability. Today, Kobe Steel is a leading screw compressor manufacturer, producing more than 10 000 units per year in three fields : air ; refrigeration and air conditioning ; and process gas. This paper introduces development in this field and related application expansions.

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104	Past and Future Developments in Hot Isostatic Pressing (HIP) Equipment
		Takahiko Ishii/Dr. Takao Fujikawa/Yoh-ichi Inoue/Takeshi Kanda
		HIP developmental history in many ways mirrors the research history of advanced materials such as cemented carbide tools, P/M tool steels, ferrite recording heads, and engineered ceramics. The requirements for HIP for each application area calls for special design. For example, to achieve higher productivity, higher working temperatures, and, often, a special atmosphere inside the processing chamber are called for. This paper describes the history and recent trends in this technology and related high pressure equipments at Kobe Steel.

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