Research on Defects Control of Niobium Tungsten Alloy by Laser Welding

Abstract

The laser welding experiment of Nb521 niobium-tungsten alloy with 1.0mm thickness was carried out, and the effects of different welding edge preparation states, including fast wire cutting + milling and slow wire cutting + no milling, on the weld formation were analyzed. The results show that the laser weldability of the niobium-tungsten alloy is very good. The welding parameters are in a wide range, and good weld formation can be obtained easily. The effect of the welding edge preparation states on weld formation is very small, and all of the welded joints are broken in the base metal zone far away from the weld beam. Based on laser welding, the forming analysis of argon arc repair welding was carried out. The defects such as cracks and oxidation could be controlled effectively by optimizing the welding process. When the ratio of argon arc repair welding is in the range of 30% to 50%, the welded joints still have good tensile properties. The average tensile strength reaches 98.9% of the base metal and the average elongation after fracture reaches 83.8% of the base metal.