Mitigation of harmful effects of welds in zirconium alloy components
- AECL Research, Chalk River, Ontario (Canada). Chalk River Labs.
- Webster (R. Terrence), Scio, OR (United States)
Welding produces local residual tensile stresses and changes in texture in components made from zirconium alloys. In the heat-affected zone in tubes or plates, the basal plane normals are rotated into the plane of the component and perpendicular to the direction of the weld. Thin-walled Zircaloy-2 tubes containing an axial weld do not reach their full strength because they always fail prematurely in the weld when pressurized to failure in a fixed-end burst test. Reinforcing the weld by increasing its thickness by 25% moves the failure to the parent metal and improves the biaxial strength of the tube by 20 to 25% and increases the total elongation by 200 to 450%. In components made from Zr-2.5Nb, the texture in the heat-affected zone promotes delayed hydride cracking (DHC) driven by tensile residual stress. Although the texture is not much affected by heat-treatments below 630 C and large grain interaction stresses remain as a result of mixed textures, macro-residual tensile stresses can be relieved by heat treatment to the point where the probability of cracking is very low.
- OSTI ID:
- 55657
- Report Number(s):
- CONF-930611-; ISBN 0-8031-2011-7; TRN: 95:012902
- Resource Relation:
- Conference: 10. international symposium on zirconium in the nuclear industry, Baltimore, MD (United States), 21-24 Jun 1993; Other Information: PBD: 1994; Related Information: Is Part Of Zirconium in the nuclear industry: Tenth international symposium. ASTM STP 1245; Garde, A.M.; Bradley, E.R. [eds.]; PB: 818 p.
- Country of Publication:
- United States
- Language:
- English
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