【摘 要】
：
The GH4169 superalloy with different content of δ-Ni3Nb phase was welded by tungsten inert gas welding.A detailed study of microstructure and hardness of heat-affected zone (HAZ) was performed in both as-welded and aged state.The results show that the pre
【机 构】
：
School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China;Tianjin Key L
论文部分内容阅读
The GH4169 superalloy with different content of δ-Ni3Nb phase was welded by tungsten inert gas welding.A detailed study of microstructure and hardness of heat-affected zone (HAZ) was performed in both as-welded and aged state.The results show that the precipitation of δ phase,especially the intergranular δ phase,can lead to the enrichment of Nb and Mo elements,which promote the formation of γ/Laves eutectic constituent at grain boundaries in HAZ.In as-welded state,the hardness decreases first and then increases (exhibiting a “V” shape) with distance away from fusion line in HAZ,which is governed by grain size.After aging treatment,however,the γ\'\'phase plays a key role in hardness and leads to the “∧” shape profiles of hardness in HAZ.
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