Alloy 603 GT is a newly developed cobalt-free Ni-base alloy. The composition of the alloy guarantees excellent high temperature strength due to the high carbon content of 0.2 -0.4 wt.-% resulting in primary precipitated chromium carbides. These carbides are homogeneously distributed and provide high thermal stability so that resolutioning during service cannot occur, thus preventing grain growth and maintaining the long term mechanicalproperties. Superior high temperature corrosion resistance up to 1200°C (2192°F) is provided by the formation of alumina scale due to the high aluminum content of 2.4-3.0 wt.-% in the alloy. Additions of yttrium up to 0.1 wt.-% improve the spallation resistance under thermal cycling by the formation of very thin and tight oxide layers. Working, machining and processing can easily be done using conventional techniques. Welding with the matchingfiller metalprovides mechanicalstrength and oxidationresistance similar to the parent metal.
Keywords: Alloy 603 GT, welding, mechanical properties, oxidation resistance