Trial Production of GH1059 Alloy Guide Tube for Control-rod Drive Mechanism of Sodium-cooled Fast Reactor

The GH1059 alloy is made via the vacuum-induction and protective atmosphere electroslag remelting process.Then the guide tube with OD 186 mm and ID 104 mm is successfully manufactured by means of the processes,namely forging,hot-extrusion,and 2-pass cold-rolling.The inspection and testing results of the tube show that the GH1059 alloy guide tube features excellent surface quality and dimensional accuracy,full austenite structure matrix with average grain size of about 78.23μm;approximately circular carbides containing Cr,Fe,Ni and Mo are distributed in the grains,while the lamellar carbides rich in Cr and Mo are distributed in the grains and at the grain boundary as well;and the guide tube also has excellent tensile properties,hardness and impact toughness,and corrosion resistance against copper-copper sulfate-16% sulfuric acid and nitric acid.The localized GH1059 alloy guide tube has all of its technical indexes up to relevant application requirements.