[ Duplex Infrastructure ]
[ Duplex Infrastructure ]
Duplex plate excels in demanding dam project
The recently completed Tateno Dam in the Kumamoto Prefecture of Japan is designed specifically for flood control . Thick plates in duplex stainless steel SUS821L1 have played a critical role in the manufacture of hardwearing yet lightweight equipment .
By Joanne McIntyre , Stainless Steel World
The Tateno Dam was constructed for the specific purpose of flood control . Located in the Shirakawa River Basin , an area of steep hillsides that receive higher rainfall than the national average , it has a catchment area of 383 km ². The dam impounds about 36 ha of land when full , and can store 10,100 thousand cubic meters of water . The dam has been built on the west side of Aso Caldera River , which flows through the centre of Kumamoto City , a region that has suffered from
The upstream side of Tateno Dam . Photo © NSSC
significant flood damage in the past . During normal weather conditions , water is allowed to flow freely down the river , while during heavy rainfall and snowmelt , excess water is temporarily stored at the dam to prevent flooding downstream . Preliminary research on the dam began as far back as 1969 , although construction
Detail of discharge equipment ( screen / discharge pipe ). Photo © NSSC
did not start until 2018 and the dam was finally completed in March 2024 .
Thick duplex plate Thick duplex stainless steel SUS821L1 ( NSSC 2120 ® 21 % Cr-2 % Ni-N ) plate was specified for discharge equipment in the Tateno Dam . The main body is equipped with a discharge pipe , energy reducer , rectifier plate , discharge gate , etc . to adjust the flow rate during floods and to capture driftwood and stones . The various components of the discharge equipment ( screens , pipes , gates etc ) are exposed to strong water currents and impacts from rocks and other debris , making high strength and wear resistance essential . Initially , general-purpose SUS304 austenitic material was considered . However , duplex SUS821L1 was ultimately specified as this high-strength material enabled the construction of a lighterweight design . The duplex grade is approximately twice as strong as SUS304 . The use of SUS821L1 significantly reduced construction costs as , due to its superior strength , less material was required so the equipment was lighter , while also benefitting from excellent corrosion resistance and high abrasion resistance .
20 Stainless Steel World June 2024 www . stainless-steel-world . net