Investigation of structure and connection properties of Zr-%1Nb sheets by pulsed laser welding process

Zirconium and its alloys are mastered for the construction of pressure vessels, nuclear, aerospace and biomedical industries due to their thermal expansion and high corrosion resistance. Grain growth is due to welding heat in welded metal and HAZ. Nd.YAG laser welding was performed on Zr-1Nb sheets with a thickness of 0.7 mm without filler metal at different speeds. Eye test was used to investigate welding quality, size of welding areas, optical microscopic examination for grain size, structure and hardness test in terms of Wickers. Discussion and results showed that the inlet heat depending on the electric current and welding rate caused grain growth in welded metal and in HAZ, the lower the growth of the seeds due to thermal grades. Microstructure of welded metal was shaped according to the cooling rate of the basket or needle structure. WeidmannStaten HAZ structure is a rough needle. Welded metal HAZ a higher hardness than haz area, which shows that along with grain growth, hardness also increases in welded areas.

کلیدواژه ها:

Zr-%1Nb ، Pulsed laser welding ، Grain growth ، Weidmann Staten ، Basket structure ، Hardness test.