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Steel Plates for Bridges and Structures
In order to make effective use of such confined environments, it is necessary to improve the functions of small tracts of land for better ways of living by such means as improving roads and railways and building medium- and high-rise buildings. A great number of buildings were constructed during the period of high economic growth by socioeconomic plans, while improvement of the social infrastructure must continue to be pursued. A large amount of steel plates are used for main parts of bridges and buildings. Sumitomo Metals inaugurated operation of a wide 4-high steel plate rolling mill at Wakayama Steel Works in 1965. (The operation was discontinued in December 1986.) In 1970 at Kashima Steel Works, a rolling stand with a roll of 186 inches in body length was installed. And in 1974 the Steel Works established a system for manufacturing ultra-wide steel plates up to a maximum width of 5.1 meters, the world's largest class, by adding a stand with a roll of 210 inches in body length. By means of such inordinately-equipped facilities and excellent technical staff, SMI is supplying steel plates with flat and beautiful surfaces. In addition, various kinds of steel grades with high-class weldability and atmospheric corrosion resistance are available, satisfying application conditions and objectives that may change with the times. As we will never spare efforts in conducting research and development of new steel grades and technologies so that we can justify customers' trust in us, we would appreciate it if customers would continue to consider our products. 1. Strict quality control SMI aims at improving precision and uniformity of products, using excellent materials obtained under an integrated iron- and steel-making management system. Furthermore, process control by a large computer enables each product to be assured of good quality controlled manufactured products. In December 1993, the Company completed registration of its certified quality system on the basis of ISO 9001. 2. Excellent dimensional accuracy Precision in plate thickness has been remarkably improved by means of a powerful rolling stand and automatic gauge control equipment. In addition, measuring instruments on the rolling line and the finishing line help give more precision in dimensional control. 3. Good surface condition Scale is completely removed from the surface by a descaler with high pressure water. In addition, the surface is cleared of secondary scale with a steam jet in the course of rolling. Meanwhile, walking beams are employed to move steel plates so that they are finished with beautiful surfaces. 4. Satisfactory flatness In regard to short corrugation inevitably produced by a 4-high rolling mill, though with careful attention paid to its prevention, a powerful hot leveler with 3,000 tons in straightening reaction force is used to produce substantially flat steel plates. 5. Max. 5,160mm-wide steel plate available By use of a rolling mill with a roll of 5,334-mm in body length, SMI manufactures 5,160-mm ultra-wide steel plates. It is possible to produce such a large-sized one of 25,000mm in max. length. 6. New steel plate-making processes developed SMI manufactures high tensile steel plates featuring excellent weldability, following the DAC process (Dynamic Accelerated Cooling process) developed as a result of application of the SSC process (Sumitomo's Special Controlled Rolling process) and accelerated cooling. These manufacturing processes are generically known as TMCP (Thermo-Mechanical Controlled Process). |
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