Site:           Kobe Steel, Ltd.
                Kobe Corporate Research Laboratory
                Electronics Research Laboratory
                1-5-5, Takatsukadai, Nishi-ku
                Kobe 651-22, Japan
                http://www.kobelco.co.jp/indexe.htm
Date Visited:   6 June 1996
WTEC Attendees: J. Willis (report author), 
                D. Gubser, 
                D. Larbalestier, 
                M. Suenaga
Hosts:          Dr. Takefumi Horiuchi, Senior Technical Director, 
                   Electronics and Information Division
                Dr. Rikuo Ogawa, General Manager, 
                   Electronics Research Laboratory
                Dr. Yoshio Kawate, Director, 
                   Electronics Research Laboratory
                Kazuo Takabatake, General Manager, 
                   Electronics and Information Div., and 
                   President, Japan Magnet Technology
                Dr. Masao Shimada, Manager, 
                   Superconductivity Research Section 
                   (now Manager, Advanced Products Development Ctr., 
                    Technical Development Group, Kobe Steel)
                Dr. Seiji Hayashi, Senior Researcher, 
                   Superconductivity Research Section
                Dr. Takayuki Miyatake, Senior Researcher, 
                   Superconductivity Research Section
                Ryoichi Hirose, Senior Researcher, 
                   Superconductivity Research Section
                Dr. Kazuyuki Shibutani, Researcher, 
                   Superconductivity Research Section
                Dr. Yoshito Fukumoto, Researcher, 
                   Superconductivity Research Section

BACKGROUND

Kobe Steel is a large (19,400 employees in 1994), diversified company founded in 1905. It has four primary product areas: (1) iron and steel, (2) aluminum and copper, (3) engineering and machinery, and (4) electronics and information technology. Long-range corporate goals call for maintaining steel as the core business. Kobe Steel expects the aluminum and copper and the machinery sectors to provide a broad base for growth. The goal for the electronics and information sector is to expand into semiconductors, factory automation, and robotics.

Net sales for the years ending 31 March 1994 and 1995 were $10.68 billion and $10.66 billion, respectively, for operating incomes of $359 million and $571 million for the same periods. For those years, the company recorded net losses of $10 million and $957 million, respectively. The losses reflect weak economic conditions due to Japan's recession, the appreciation of the yen, and the severe damage to production facilities, housing units, and corporate headquarters caused by the Great Hanshin Earthquake, which struck Kobe in January 1995. Product sector sales are iron and steel (45%), aluminum and copper (22%), and machinery, engineering, and electronics (33%). This latter sector has been showing the strongest growth. The Kobe Steel Group has over 70 overseas subsidiaries and affiliates in the United States, Europe, and Asia. Kobe Steel has a joint venture with USX in Ohio (USS/Kobe Steel Co.) to produce various steel products and a joint venture with Texas Instruments (KTI Semiconductor, Inc., located in Japan) that produces 9,000 8-in. silicon wafers per month.

CORPORATE LABORATORY ORGANIZATION

Besides the four main business divisions listed above, there is a Technical Development Group primarily located at the Kobe Corporate Research Laboratories at Seishin Industrial Park in western Kobe, at which a total of about 1,000 employees work. This laboratory is divided into five research laboratories: (1) Materials, (2) Mechanical Engineering, (3) Chemical, Polymer, and Biotechnology, (4) Process Technology, and (5) Electronics. The Superconductivity Research Section is one of seven research areas within the Electronics Research Laboratory.

SUPERCONDUCTIVITY

Kobe Steel established its first superconductivity and cryogenics laboratory in 1964. In 1985 there was a major reorganization of the corporate laboratories, and these activities were dispersed into the Mechanical Engineering, Materials, and Electronics Research Laboratories. When high temperature superconductivity (HTS) was discovered, the researchers were collected into the newly established Superconductivity and Cryogenics Technology Center. Major business products at this time were Nb-Ti and Nb₃Sn superconductive wire and helium liquifiers. Finally, in 1994 in another reorganization, these functions became the present day Superconductivity Research Section of the Electronics Research Laboratory.

The Superconductivity Research Section is divided into three groups:

1. the Wire Group, which works on metallic superconductive wire
2. the Magnet Group, which performs R&D on superconducting magnets, mostly nuclear magnetic resonance (NMR) magnets
3. the Applications Group, which works on HTS materials, cryogenics, novel magnets, and new applications

HTS Research Topics

The logical progression of development is seen as R&D -> Products -> Markets. There is an established and expanding market for NMR magnets, which require wire, magnets, and cryostats. The goals for these products are to improve the performance of the system and reduce the cost. New markets being explored are cryogen-free "dry" magnets and novel testing equipment, such as the watermelon magnetic resonance imaging (MRI) system. Work on HTS materials is directed toward current leads for the dry magnets and coil inserts for high frequency (high field) NMR magnets. This research is concentrated on Bi-2212, because the application is at 4.2 K, and high J_c, high "n value" (J = Eⁿ, where J is the current density and E is the electric field), and thus low loss, wires are easier to make from this material than from Bi-2223. To increase the strength of the (round) wire to withstand the large Lorentz forces at high magnetic fields, multifilamentary wire is being produced. The first stack of wire uses pure silver for chemical compatibility with the Bi-2212, but this is then put into an outer tube of silver alloyed with Ni and Mg in what is called "double sheath" wire. A small coil has been produced this way and has generated a field of 0.2 T in a background 21 T field. A persistent current switch is also being developed for monofilament Bi-2212 wire. At present, a coil generating 0.1 T shows a decrease of ~90% in the magnitude of the trapped magnetic field in the first 10 minutes after the persistent switch is closed; after that it is very stable. Such a device would be required in a 1 GHz NMR system.

Superconductivity Business Strategy

Kobe Steel's business activities related to superconductivity largely take place through Japan Magnet Technology (JMT), a joint venture between Kobe Steel and Magnex, a magnet-making company in the U.K. Business opportunities being considered relate to energy, transportation, NMR, and others. All but NMR are mostly large-scale, requiring substantial R&D funds. "Large-scale" usually means R&D as part of a national project, but these are unpredictable in the long term (and Kobe Steel has never been interested in the Maglev train or the SSC). Kobe Steel and JMT are taking a wait-and-see attitude on this type of project. The NMR and MRI markets are of medium size and mature, so there is much competition for magnets < 4 T. Kobe's future target area is high field NMR systems (750 MHz [=17.6 T] and higher), which also require a continuous R&D investment. The strategy is to sell wire and lower field NMR and MRI magnets to support the high field NMR magnet research. Product sales also allow Kobe Steel to maintain an R&D base to prepare for future large-scale business opportunities.

Kobe Steel began producing Nb-Ti wire in 1973 and Nb₃Sn wire in 1983. In 1984 it built a 1 MJ SMES and a high field resonance magnet. In 1990, it established JMT, the joint venture with Magnex. In 1993, Kobe Steel began making high "n-value" Nb₃Sn by the bronze process. In 1994, JMT delivered the world's first 750 MHz magnet to Pennsylvania University. In 1995 Kobe Steel developed the watermelon MRI system. Kobe Steel currently has about 50% of the Nb₃Sn wire market for NMR systems (Vacumschmelze has the rest). In 1995, 100% of the magnets for the NMR systems sold by JEOL, Ltd., were produced by Kobe Steel and JMT; some magnets were also sold to the other two producers of NMR systems. The target for 1996 was an 800 MHz magnet. JMT management would also like to produce magnets for the "NMR Park" proposed by the Science and Technology Agency (STA).

Table Kobe.1 shows the annual output of Kobe Steel, JMT, and Magnex, and their technical contributions. NMR magnets presently produced by JMT and Magnex are 300, 400, 500, 600, and 750 MHz. In planning stages at the time of the WTEC visit were magnets of 800, 850, 900, 950, 1,000, and 1,050 MHz. Magnets above 900 MHz will require HTS insert coils to attain the high fields.

Table Kobe.1
Kobe Steel and Affiliates Superconductor Business:
Ownership, Products, Production, Sales, and Technical Contributions

In addition to the products listed in Table Kobe.1, Kobe Steel is developing new markets such as that for its dry magnet, which is estimated to be 15-20 units per year in Japan. Figure 4.20, p.57, shows the first page of an advertisement for this magnet. Kobe's 10 T 100 mm bore entry in the field is unique in that it is rotatable from a vertical to a horizontal bore. It uses a Nb-Ti/Nb₃Sn magnet and Bi-2223 current leads to reduce the heat leak. HTS current leads are also applicable to NMR and MRI magnets. Growth areas for MRI magnets are for cryogen-free and open (split magnet) systems.

Another new market area is "watermelon MRI." There is a real market in Japan for this product, where a watermelon typically costs $30 and the consumer wants to be sure he is getting a good one. The technology was developed for the Japan Farmers Union to detect voids and measure sugar content to assess quality and ripeness. The system developed can examine a melon for voids in 1 s and assess the sugar content in 6 s using sophisticated NMR pulse techniques. Figure Kobe.1 shows the apparatus and scans of a good and a defective melon. The characterization adds an additional 1.5¢ to the cost of a melon, prorated over the eight-year life of the equipment. Kobe Steel expects orders for four to six of these units per year at a price of approximately $1.0 million each.

Fig. Kobe.1. MRI system for determining void and sugar content of watermelons. Scans of a good (a) and a defective watermelon with voids (b).

Kobe Steel and JMT hope to develop markets for 1 GHz and higher NMR magnets and a custom made cryocooled (at over 20 K) superconducting magnet over the next 20 years.

On a short tour, the WTEC team saw some of the HTS work on double sheathed Bi-2212 wire, persistent current switches, and insert magnets. Team members also saw the watermelon MRI analyze a set of watermelons in real time and surprisingly rapidly. Several employees were winding magnets, both in a room for that purpose and, because of limited space and expanding demand, out on the main floor. A recently assembled 750 MHz magnet was quite compact compared to others available commercially.

Personnel

Staffing has been increasing in recent years by the addition of part time employees. R&D work is performed by 20 persons, 5 for HTS and 15 for LTS. Wire production (Kobe Steel) has 20 permanent and 25-30 part-time workers. Magnet production at JMT had 20-25 permanent employees and an extra 25 in June 1996. Thus there are a total of about 120 employees working on superconductivity at Kobe Steel and JMT.

Conductor and Materials Development

Kobe Steel is doing R&D on Nb-Ti, bronze process Nb₃Sn, and Bi-2212. Its most significant contribution to HTS conductor development is achievement of high strength and high critical current density by development of double (Ag-alloy/Ag)-sheathed Bi-2212 conductors for solenoid coils. Major technical challenges are seen to be achievement of homogeneous microstructures over long lengths, superconducting joints, and persistent current switches. Current Bi-2212 multifilament conductor properties are J_c >10⁵ A/cm² and J_e >5 x 10⁴ A/cm² at 4.2 K and 0 T; I_c x L = 13.4 kAm (4.2 K, 0.4 T) for rectangular wire, and 57.2 kAm (20 K, 1 T) for tape.

Generation and Storage, Transmission, and Distribution

Kobe Steel has no direct activities in this area; however, it has been a member of the Super-GM project. The major contribution of Kobe Steel to this project is the research and development of Nb₃Sn superconducting wire for ac use. Kobe Steel specializes in powder metallurgically processed Nb₃Sn wire as one of the candidates.

End User Applications

This primarily means high field NMR magnets and, to a smaller extent, cryocooled magnets and other new applications. Some work is being done in collaboration with external organizations, such as the National Research Institute for Metals (NRIM) and the Institute for Metals Research at Tohoku University. Work is primarily on a collaborative, no-funds-exchange basis.

Kobe Steel anticipates an end user market for HTS materials in 20 K cryocooled magnets and very high field (>850 MHz) NMR magnets. There is no competition from LTS systems in these areas. Kobe management expects commercialization for high field superconducting magnets, such as a 1 GHz NMR magnet, a 1.5 GHz NMR magnet, and a custom made cryocooled (at over 20 K) superconducting magnet, to take place in 5, 10, and 20 years, respectively. Other new markets for magnets will be for LTS and HTS cryocooled magnets, split MRI magnets, cryocooled HTS MRI magnets, HTS + LTS NMR magnets for >850 MHz, and novel applications (such as the watermelon MRI).