In this issue. No. 295 September Nippon Steel s Automotive Steel Sheets. Carbon Fibers and Carbon-fiber Composite Products.

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1 No. 295 September 2002 Published monthly by Public Relations Center Corporate Secretariat Div. Nippon Steel Corporation More about Nippon Steel WWW Notice If you have received the web-version of Nippon Steel News via , you are already a registered subscriber, thus no new registration is required. Associates who wish to become subscribers are requested to click on the icon to complete and submit the registration form. Upon registration the monthly web-version newsletter will be sent directly to the submitted address. In this issue Part 2 Advanced steel solutions simultaneously attain light weight and crash safety of automobiles. Part 2 Steel-Canvas Series by Hiroji Noda "Windbreak" (Born in 1952, his art combines abstract painting with other materials. He was awarded the 2001 Newcomer Prize by the Minister of Education, Culture, Sports, Science and Technology.) Nippon Steel Composite is renovating conventional concepts and methods by use of its carbon-fiber composite products.

2 Part 2 Advanced Steel Solutions Simultaneously Attain Light Weight and Crash Safety of Automobiles. Joining technology Joining process development Quality guarantee technology for joints Application technology of automobile makers Tailored blanking Forming technology Plastic forming Lubrication technology In this two-part series (previous and current issues), Nippon Steel s new operating moves in automotive steel sheets are discussed focusing on: Part 1: Global operations (previous issue) Part 2: Steel solutions In the current Part 2, Nippon Steel s steel solutions that take into account steel applications in automobiles from forming at automobile makers to assessment of automobile parts performance are introduced below. Nippon Steel s High and Comprehensive Technological Capabilities Concentrated on Automotive Steel Sheets Material assessment and design Composition design Process metallurgy TRIP steel and other high-performance high-strength materials Development and commercialization of optimized steel materials for automobile applications Surface treatment technology Interface control Corrosion-protection technology Hydroforming Analysis technology FEM analysis Material analysis Design/engineering technology Mechanical/measurement/ control technology Thermal and process technology

3 Advanced Technology of Nippon Steel Contributes to ULSAB-AVC Program The ULSAB-AVC (UltraLight Steel Auto Body-Advanced Vehicle Concepts) Program of the International Iron and Steel Institute started in January 1999 with the participation of 33 world steelmakers including Nippon Steel. Its major aim is to design the virtual model of the entire automobile structure and to prove steel s potential for reducing automobile weight. In the current project, total weight reduction of automobiles has been pursued and application of high-strength steel in nearly all automobile parts showed outstanding results weight reduction below benchmarked vehicles by 19% for a 1.5 liter-class virtual model and 32% for a 2.5 liter-class virtual model. Lightweight virtual models have achieved outstanding ratings in computer simulation testing. The two virtual models have cleared the ACEA commitment on CO2 emission reduction to 140 g/km set for In addition, the two models tested safe enough to potentially qualify for the fivestar crash rating, the highest possible in the New Car Assessment Program a crash safety test of Europe and the United States proposed for Nippon Steel has participated in the ULSAB- AVC Program to prove that steel is the only material that can realize automobiles with less impact on the environment, higher safety and at low cost. By incorporating research results thus obtained into its own material and application technologies, the company is extending diverse endeavors in further enhancing the value of high-strength steel materials in terms of lighter weight and improved safety of automobiles. Nippon Steel s advanced technologies in the field of automobile steel sheets are introduced below. Tube Hydroforming Hydroforming Technology Creates Structurally Efficient Design In hydroforming, steel pipe is expanded by means of hydraulic pressure to precisely conform to the specified shape. The technology obviates the need for flanges used for spot welding of formed parts and thus is indispensable for reducing automobile weight. Further, it offers cost cutting

4 through improved forming precision, reduction in the number of parts and process elimination, and accordingly the adoption of hydroforming technology is rapidly spreading among automobile makers. Nippon Steel s strength in this field is the combined use of a facility to manufacture prototype full-size parts and the highly precise analysis Tailored Blanks Utilize Advanced Laser Welding Technology Tailored blanking is the technology in which two steel sheets having different thicknesses and strengths, after weld joining, are solidly formed by means of presses. It allows application of highstrength steel sheets in only the structural section requiring strength, thus making possible weight reduction of the section requiring no strength and excess thickness while retaining the necessary strength of the formed parts. In the field of tailored blanks, which facilitate weight reduction and improved crash safety, Nippon Steel is implementing optimization of the welding process key to tailored blanking, accurate technology by use of the finite element method (FEM). The company is conducting rapid trialmanufacture and optimum material proposals by making the most of the combined use of such facility and technology. Meanwhile, Nippon Steel is the major supplier of steel pipe for hydroforing applications in Japan, the demand for which is expected to considerably increase in the future. assessment of tailored blanks during forming and performance assessment of finished parts, which has successfully led to the establishment of highly reliable application and forming technologies. Laser welding is the major joining process in welding of tailored blanks. Nippon Steel has established the superiority of laser welding by means of analysis technology. In the ULSAB- AVC, the high-strength steel + laser welding technology has been extensively adopted as an optimum combination and such welding has reached 114 m per vehicle. High application effects are expected to be brought about. Tailored Blanks (Example in ULSAB) Body application example Press forming, after weld joining, of two steel sheets having different thicknesses and strengths, allowing lighter weight of the section requiring no strength Side panel outer 0.7mm 0.9mm Strength level 1.3mm 340MPa 390MPa 490MPa 1.5mm 1.7mm

5 High-strength Steel Technology Meets Lightweight and Safety Needs High-strength steel can meet the higher strength and lighter weight being demanded for automobile steel sheets. Application of high-strength steel in automobiles is now more than 30% of the bodyin-white on average and 50% for those requiring higher application. For high-strength steel materials for automobiles, required characteristic performances are different depending on the parts, and thus user needs are becoming more diverse. In general, 590 MPa class is being applied in the body-in-white, and 980 MPa class for such Application and Forming Technologies Supported by Advanced FEM Analysis Technology Concurrent with the wider application of highstrength steel materials, the integrated research across materials and application/forming technologies is becoming more important for steelmakers so that automobile makers can more appropriately utilize high-strength steel materials. Nippon Steel is promoting R&D through joint endeavors with automobile makers to quickly provide best steel solutions. Representative is TRIP (transformation-induced components as bumpers and door impact beams. The current task to expand high-strength steel application for further weight reduction is how to make appropriate balance between strength/formability and crash safety. In order to cope with the need for improved fuel efficiency and enhanced crash safety, Nippon Steel is promoting research and development on its proprietary technologies and jointly with automobile makers so as to provide a rich menu of high-strength steel materials. plasticity) steel, which received Japan s Okouchi Award for excellent R&D achievements in material production and application in High assessment has been given to the steel because two key performances crash safety and press formability have been simultaneously achieved. TRIP steel, together with DP (dual-phase) steel and BH (bake-hardening) steel, was developed earlier by Nippon Steel as high-strength steel, but it was the FEM analysis technique, a technology to analyze Forming Simulation by Means of FEM Analysis Technology Corresponding stress

6 the instantaneous deformation characteristics during a simulated automobile crash, that proved the excellent crash safety performance of TRIP steel. These steel solutions have not only allowed the instantaneous understanding of crash phenomena, conventionally difficult with other approaches, but also established the method to assess the material characteristics under high-speed deformation. The FEM analysis technique is acclaimed as world-class technology even in academic circles. Application of Laser Welding Technology Is Expanding Laser welding induces less deformation and no deterioration in material properties. Further, because of its one-side welding unlike spot welding, laser welding brings about enhanced structural freedom and secures improved appearance. It has recently been adopted not only for welding tailored blanks and other parts but also for assembling body components such as roofs and side panels. Nippon Steel has long noted the importance of joining technology and promoted R&D on such technology for use in diverse fields such as shipbuilding, tanks and automobiles. Fully utilizing these research results, current R&D endeavors are being directed to clarify the strength characteristics of laser welded joints. Based on the accumulated research data thus obtained, the company is proposing optimum Global environment Collision safety Development of Joining Technologies in Automotive Field Reduction of environment-burden substances Lightweight vehicle structure Renovated body structure Improved rigidity of body joining conditions including material selection and extending research efforts for solving technical tasks of automobile makers so as to expand the application range of high-strength steel materials in automobiles. Lead-free steel sheet for fuel tank High-strength steel Tailored blanking Optimized parts design Hydroforming Development of optimized joining technology Laser Spot Arc Seam Plasma

7 Carbon Fibers and Carbon-fiber Composite Products Part 2 Nippon Steel Composite Is Renovating Conventional Concepts and Methods by Use of its Carbon-fiber Composite Products. Nippon Steel Composite Co., Ltd. supplies highperformance composite materials produced using carbon fibers. The company was established by acquiring the TOWSHEET (earthquake-resistant reinforcing sheet) business from TONEN Corporation and by spinning-off Nippon Steel s carbon-fiber composite material business. Three major products of Nippon Steel Composite are: Steady efforts by Nippon Steel s carbon fiber and composite products divisions have yielded substantial results. The two companies of the Nippon Steel Group are spearheading business developments as described in this two-part series (previous and current issues): Part 1: Nippon Graphite Fiber Corporation (previous issue) Part 2: Nippon Steel Composite Co., Ltd. Nippon Steel Composite Supplies Advanced Carbon-fiber Composite Products for Diverse Applications TOWSHEET: Concrete-structure reinforcing sheets made of carbon fibers, used for maintaining and repairing social infrastructure NOMST members: Concrete members reinforced with carbon fibers for the NOMST (novel material shield-cuttable tunnel-wall system) method, used in great-depth shield tunnel construction Composite materials for industrial uses: Composite materials making the most of the extralight- TOWSHEET

8 weight, high strength and high elasticity peculiar to carbon fibers, used as material for construction and precision machine parts TOWSHEET Prolongs Service Life of Infrastructures The concept for social infrastructure in Japan is radically shifting from scrap and built to prolonged service life and thus maintaining and reinforcing methods are becoming important in terms of infrastructure improvement. In this regard, the TOWSHEET method is attracting increasing attention as an effective maintaining/reinforcing method, in which TOWSHEET, manufactured by forming carbon fibers into sheets, is attached to the concrete surface of structures using cold setting adhesive resins. In Japan, maintenance needs are arising for superannuating infrastructure. Along with the increasing size of vehicles and increasing traffic volume, highways are superannuating at an unanticipated rate, posing the need for their early These three products lines are acquiring high market acceptance and contributing to the business development of Nippon Steel Composite. maintenance and repair. Further, appropriate maintenance under harsh environments is required for sewerage and waterworks, and ports and harbors. TOWSHEET meets these maintenance and repair requirements. In the building construction field, Nippon Steel Composite has developed a TOWSHEET earthquake-resistant reinforcing method for buildings in use. Application needs for such method are expected to increase for department stores, condominiums, public apartment buildings, and school and hospital buildings. Distinctive features of TOWSHEET are that while its initial cost is slightly high, its application is simple, and that because of its freedom from rust, maintenance and life-cycle costs are considerably reduced. Earthquake-resistant reinforcing of bridge piers using TOWSHEET

9 NOMST Allows Safe Tunnel Construction in Shorter Term The NOMST (novel material shield-cuttable tunnel-wall system) method is adopted for the earthretaining walls of the vertical shafts in which tunnel construction starts and ends. With this method, the earth-retaining walls to be cut through by the shield machine are made of limestone concrete and reinforced with carbon fibers. The shield machine can easily penetrate the earth-retaining wall to excavate the tunnel. The method exploits the characteristic properties of carbon fibers: they have high strength several times that of steel but are low in compression and shear strength. In the conventional method, because the retaining wall was constructed using reinforced concrete and wide-flange beams, it was necessary to make ground improvement in advance and manually remove concrete and steel reinforcing for the progress of the shield machine. The NOMST method eliminates such ground improvement and dangerous manual works, lowers construction costs and environmental impacts and reduces the construction term. Since the first application more than ten years ago, the method has been used in more than 120 projects. NOMST is extensively being used for the construction of subway tunnels in the Tokyo metropolitan area, underground multi-purpose ducts and conduits for electric cables. NOMST precast members Carbon-fiber Composite Products Are Growing in Industrial Applications The third pillar of Nippon Steel Composite s carbon-fiber composite material business is industrial applications. Long years of endeavor in market development by the company have led to the accelerated diffusion of carbon-fiber composite materials in industrial fields, supported by the arrival of advanced information-oriented society. A typical example is application in the rolls of highspeed rotary presses for printing newspapers and others. Newspaper companies have asked for Shield machine start for excavation

10 higher-speed rotary presses for faster delivery and to promote color printing of newspapers. To this end, because carbon-fiber composite rolls are lightweight and highly rigid, and can secure highspeed and precision printing, their application has advanced quickly, accounting for a large share in printing rolls. For the robot arms used in the transfer of products in the liquid-crystal display production process, pitch-type carbon fibers are increasingly being adopted to meet the need for light weight, high speed, precision and rigidity compared to the PAN-type fibers. In the field of carbon-fiber composite products for industrial uses, the technical capability of Nippon Steel Composite has been highly assessed among users by always pursuing precisely the essential performances by application field, which are critically being called for by users, and developing the proposal-type-products, which supply solutions for users. Carbon-fiber composite rolls of high-speed rotary press for printing newspapers All copyrights reserved by Nippon Steel Corporation HEAD OFFICE Public Relations Center 6-3, Otemachi 2-chome, Chiyoda-ku, Tokyo , Japan Phone: Fax: to 5609 OVERSEAS OFFICES New York Phone: Fax: Chicago Phone: Fax: Houston Phone: Fax: Düsseldorf Phone: Fax: London Phone: Fax: Sydney Phone: Fax: More about Nippon Steel on the website: Singapore Phone: Fax: Bangkok Phone: Fax: São Paulo Phone: Fax: Beijing Phone: Fax: Shanghai Phone: Fax: Guangzhou Phone: Fax: Thank you. issue coming soon.