Nitrogen Effect on the Microstructure and Mechanical Properties of Nickel Alloys

作者：Nabavi B^*; Goodarzi M; Amani V

来源：Welding Journal, 2015, 94(2): 53S-60S.

• Nitrogen
• Alloy 263
• Alloy X
• Gas Tungsten Arc Welding (GTAW)
• Equiaxed Dendrites
• Ultimate Tensile Strength (UTS)

In this research, the effects of nitrogen addition in Ar gas on weld metal microstructure and mechanical properties of Alloy 263 (UNS N07263) and Alloy X (UNS N06002) were studied. Autogenous gas tungsten arc welding (GTAW) was employed by adding 0-4 vol-% N-2 in Ar. Welding speed and heat input rate were measured as functions of gas composition. The weld metal microstructure was studied by optical and scanning electron microscopy. Experimental results demonstrated that the dendritic structure of the weld was refined by increasing N-2 in Ar for both alloys. An addition of 4 vol-% N-2 to Ar decreased significantly the columnar region in Alloy 263 fusion zone (FZ), while no similar change was observed in Alloy X. This difference is discussed based on microstructural characterization. Finally, it was found that the tensile strength and hardness have been augmented with increased nitrogen in the shielding gas.

• 出版日期2015-2