Material characterization, mechanical properties and corrosion resistance analysis of laser welded joint of pure zirconium tube

Abstract This paper investigates the material characterization, mechanical properties, and corrosion resistance of laser-welded joints of R60702 pure zirconium tubes. The study found that the hardness of the weld zone (WZ) after laser welding is significantly higher than that of the heat-affected zone (HAZ) and the base material (BM), with values of 280 HV 0.1 , 167 HV 0.1 , and 158 HV 0.1 , respectively. Tensile testing showed that the plastic deformation of the laser-welded samples was 36.8% lower than that of the base material, but the maximum stress values were similar. Fatigue testing indicated a decrease in the fatigue resistance of the zirconium tubes after laser welding, with fatigue fractures primarily occurring at the weld. Microstructural observations revealed that laser welding caused changes in the microstructure within the WZ and HAZ, forming Widmanstatten structures and α ′ phase structures. XRD and EBSD analyses revealed changes in the crystal texture of the welded joints, with the most complex texture types in the HAZ, higher texture intensity distribution in the WZ, and the simplest texture in the BM. Electrochemical test results showed that in pure acetic acid liquid, the WZ had the worst corrosion resistance, while the BM had the best.