Abstract: Hastelloy X and Haynes 230 are nickel based alloy used for combustion chamber tube of F class and G/H class gas turbine respectively. The alloys are processed into plates with thickness of 2 mm and fiber laser are adopted for the welding. Welded joints as welded and solution heat treated are taken into comparison and analysis. Results show that, As to Hastelloy X as welded, it’s of high hardness and weak toughness with network carbides precipitated in weld beam. While after solution heat treatment, palisade tissues and brittle Fe2W phase are present in weld beam. As for Haynes 230 as welded, it’s of smaller grain size than Hastelloy X as welded. Besides, carbides are discontinuously precipitated along dendrite grain boundary. After solution heat treatment, straight grain boundary transferred to zigzag one and creep property gets improved.