Applications
Electric Power Thermal/Hydro/Nuclear Power Plant
Hydro power plants, which are a form of clean energy on par with nuclear power, have been or are now being constructed in great numbers in Japan and the Asian countries. High strength steel plates are used in penstocks for hydro power generation, and in cases where the head is large, ultra-high strength steel with 980N/mm2 grade tensile strength may be used. At the same time, high toughness is also required in these plates, and high weldability is necessary because welding work is performed under difficult environments. JFE Steel supplies the JFE-HITEN Series, which possess high toughness and weldability, in a wide strength range including tensile strengths from 570 to 980N/mm2, and has also developed the JFE-HITEN 'U2' Series, which pursues economy and safety in welding work, for applications where weldability is particularly important. In dams and gates, stainless and clad steel are used in outlet conduits. There are also numerous actual results of use of high strength 780N/mm2 grade steel in the casing and rim plate around generators.
Thermal power accounts for approximately half of Japan's generated output, and steel tubes using Cr-Mo based high temperature materials, including modified 9%Cr steel, are frequently adopted in boiler-related applications. Depending
on the fuel used, dew point corrosion may occur in flues and stacks if sulfuric oxides change into sulfuric acid. In this case, JFE Steel's sulfuric acid resistant steel and Ti clad, etc. show high corrosion resistance.
In nuclear power plants, JIS SGV480 (corresponding to SA516-70) or high strength steel JIS SPV490 is used in steel containment vessels, while ultra-heavy gauge, large unit weight JIS SQV2 is used in pressure vessels. Based on its strict quality control system, JFE Steel has an extensive record in the production of these nuclear plant materials.
