Weldability of a zirconium alloy comparing resistance and pulsed laser methods

Autor(es)

Sakamiti, Guilherme Pennachin ^{[1, 2]} ; Mota de Siqueira, Rafael Humberto ^{[1, 3]} ; de Carvalho, Sheila Medeiros ^{[3, 4]} ; Meireles, Joao Batista ^{[2, 5]} ; Fernandes de Lima, Milton Sergio ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] ITA, Technol Inst Aeronaut, Grad Program Space Sci & Technol, Sao Jose Dos Campos, SP - Brazil

^[2] Ind Nucl Brasil SA, INB, Rezende - Brazil

^[3] IEAv, Inst Adv Studies, Photon Div, Sao Jose Dos Campos, SP - Brazil

^[4] FIESC SENAI SC, SENAI Inst Laser Proc Innovat, Joinville - Brazil

^[5] Fed Fluminense Univ UFF Volta Redonda, Met Engn Postgrad Program, Volta Redonda - Brazil

• Tipo de documento: Artigo Científico
• Fonte: NUCLEAR MATERIALS AND ENERGY; v. 20, AUG 2019.
• Citações Web of Science: 0

Resumo

The current study intends to characterize the microstructure resulting from the autogenous welding of zircaloy-4 and its influence on the mechanical behavior. For comparison purposes, laser beam welding (LBW) and electric resistance welding (ERW) were used for joint tubes to sleeves suitable for fuel elements of the Brazilian power reactor Angra 1. The tubes measured 14.15 mm external diameter with a wall thickness of 1.76 mm and the sleeves measured 15.61 internal diameter with a wall thickness of 0.64 mm. Under conventional ERW, the process parameters were chosen to produce an approximately 2 mm wide weld bead appropriate for the thermo-mechanical loading of the component. However, laser methods could be an alternative for automation and reproductiity. The microstructure in the fusion zone (FZ) for the welding processes was characterized by a martensite for LBW and a Widmanstatten for ERW. It was verified tin segregation in specific regions of the ERW coupons, however, without affecting the tensile strength or the hardness of the coupons. The maximum load for ERW coupons were about 8 kN, higher than LBW case (3 kN), although both above the standard requirements. The relative low value of LBW tensile strength was due to the gap between the tube and the sleeve, as conceived for ERW, and not optimized for the laser process. Loss of coolant accident (LOCA) shown a white ZrO2 coating on the LBW surface as a result of massive oxidation of the resolidified material. (AU)

• Processo FAPESP: 16/11309-0 - Estudo, desenvolvimento e aplicação de processo híbrido: Manufatura Aditiva (Ma) + High Speed Machining/Grinding (HSM/G)
• Beneficiário: Reginaldo Teixeira Coelho
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/16683-8 - Desenvolvimento experimental da soldagem a laser em altas temperaturas para aços de ultra-alta resistência mecânica para aplicações espaciais
• Beneficiário: Milton Sergio Fernandes de Lima
• Modalidade de apoio: Auxílio à Pesquisa - Regular