Hastelloy X和Haynes 230激光焊接头的组织性能

Hastelloy X和Haynes 230分别是F级和G/H级燃烧室薄壁筒体用的镍基高温合金，采用光纤激光器对2 mm厚度的两类镍基合金板材进行焊接试验，并对比焊态及焊后固溶处理的接头组织性能. 结果表明，焊态Hastelloy X的焊缝中碳化物呈网络状析出，其硬度高、韧性差，固溶处理后出现栅状组织及脆性Fe2W相. 在焊缝一次枝晶内的枝晶生长方向线性排列，取向各异，热影响区晶内也存在栅状组织. Haynes 230晶粒较小，焊缝碳化物沿树枝晶晶界链状断续析出，固溶处理后平直晶界变为弯曲晶界，蠕变性能得到提高.

Microstructure of laser welded Hastelloy X and laser-welded Haynes 230

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.