The Connection of Zircaloy-2 with Stainless Steel for Operation over a Wide Temperature Range

A method for joining Zircaloy-2 with stainless steel, using controlled expansion transition sections, is described. The transition sections consist of nickel-iron elements of the Invar type and range from low expansion rate 43% nickel-iron, at the Zircaloy-2 end, to high expansion rate 60% nickel-iron, at the stainless steel end. Problems encountered in producing suitable mechanical joints between Zircaloy-2 and 43 % nickel-iron and in preparing and welding the various grades of nickel-iron to each other and to stainless steel are discussed.