 |
|||||||||||||||
|
High Tensile Strength Steel
Sumitomo Metal had lined up SUMITEN 590 and 610 (SUMITEN 60 and 62, at that time) in the SUMITEN series before 570N/mm2 HT Grade (SM58, at that time) was adopted in JIS 3106. Since then every effort was devoted to enhance quality and performance concerned. Even now, many orders are placed to accept SUMITEN, the name trusted by customers for many years, for applications other than public structures. When 590N/mm2 grade high tensile strength steel including JIS SM570Q is outlined by applications, beams of bridges in highways and bridges with a long span come first in amount, shipment in a large amount was use for bridges with a long span, such as Minato Ohhashi Bridge and Honshi Bridge (bridge with the longest span across Akashi Strait, between Honshu and Shikoku). In the field of vessels, a large amount has been used for spherical tanks and oil storage tanks in bases of the National Oil Storage Project, such as in Mutsu-Ogawara, East Tomakomai, and Fukui. High tensile strength steel plates with strength higher than 690N/mm2 have been used for large bridges, pen-stocks in large scale power generating plants, spherical gas holders, and various types of construction machines. 1. Line-up of Plates Suitable for Various Services Emphasis is placed upon weldability and notch toughness in the material design, and steels for welding with large heat in-put (F), steels for hot working (H), and steels for zinc plated towers, etc. are provided in the Series, according to services. 2. Contribution to Reduction in Weight of Structures Since manufacturing of high tensile strength steels with high yield strength is possible through applications of process technology such as controlled rolling, accelerated cooling, quenching and tempering, etc., weight reduction in structures becomes possible. 3. Excellent Weldability Weld crack susceptibility index developed by Sumitomo is lowered as much as possible, as well as carbon equivalent, therefore, satisfactory weld joint performances for any services are achieved by use of welding materials corresponding to the respective specification. 4. Excellent Notch Toughness Sufficient considerations are given to brittle fracture resistance through manufacturing technology in relation to chemical composition, rolling, heat treatment, etc. Fracture properties are examined by the double tension tensile test, the COD test, etc. Therefore, steels can be used for large structures and vessels for low temperature services with confidence. 5. Satisfactory Corrosion Resistance and Abrasion Resistance Since high tensile strength steels contain alloying elements such as Cu and Cr, better corrosion resistance relative to common steels is guaranteed. Due to high strength, abrasion resistance is also satisfactory. |
|||||||||||||||
|
|||||||||||||||
