NKK to Supply Steel Plates for Chinese Three Gorges Dam Project
Three Gorges Dam under construction in Hubei province, China
NKK has received an order from China's Eighth Engineering Bureau of Water Resources and Electric Power to supply 13,000 tons of high-grade steel plates for use in the Three Gorges Dam hydroelectric power plant's spiral casings. The Three Gorges Dam project on the Yangtze River, being developed in Hubei province and scheduled for completion in 2009, will be the world's largest hydroelectric power plant. It will have 26 power stations each generating 700,000kW for a combined capacity of 18.2 million kilowatts,equal to about 9% of China's total power demand. The Chinese Engineering Bureau has been involved in the procurement, fabrication and installation of steel plates for the dam's casings under contract with a consortium of European heavy electrical equipment makers which won the whole power plant contract for the dam in August 1997. The Bureau selected NKK as the sole supplier in an international bid over eight other mills from Japan, South Korea and Europe. NKK's 60kg-grade high-tensile strength steel plates were highly evaluated for their technical superiority,including low-temperature weldability, coupled with the company's extensive supply record in China. This is the first time China has procured steel materials from overseas for the Three Gorges Dam project. NKK's steel plates will be used as spiral casings,or underground aqueducts, that will send water from the dam's upper sluice gate to the lower turbines. The aqueducts will require a special construction technique, with steel plates laid in a spiral to withstand the enormous water pressure.Since the casings for the Three Gorges Dam have to be welded at many spots at low temperatures,they need to be highly resistant to weld cracks. NKK responded to these requirements with its newly developed "NK-HITEN 610U2" series, which features excellent weldability and can be welded at low temperatures up to a maximum thickness of 75mm. The use of the plate can drastically improve welding productivity. In producing the plate, NKK applied the latest heat treatment technology and optimized control of the micro elements in the steel. |
