Böhler Schweißtechnik has supplied around 35 tons of welding consumables for five enormous Francis turbines at a Venezuelan hydroelectric plant.
Between 2009 and November 2012 five new Francis turbine impellers were delivered to the Guri II in Venezuela, in order to modernize one of the world’s largest hydroelectric plants. Weighting 200 tons each, with a height of 3.7 m and a diameter of 7.4 m, these are the largest and most powerful impellers ever constructed; a lot of voestalpine know-how has gone into their construction.
Using the high-performance welding process (electroslag welding) the impeller blades are welded to the impeller hub and rim. Around 4.5 tons of Böhler flux-cored wires and around 2.5 tons of Böhler metal-cored wires were processed for each of the five Guri II turbine impellers. The quality is guaranteed by the excellent mechanical properties of the filler metal and the excellent processing of the wires. Discussions are currently underway on future cooperation to manufacture new impellers of even larger dimensions, and we are testing models for a new wire with a filler metal with improved mechanical properties.