GH648合金800℃长期时效后的组织稳定性

Structure Stability of GH648 Alloy After Long-Term Aging Treatment at 800 ℃

研究了GH648合金在800℃×1 000 h下长期时效后的组织稳定性。结果表明:合金经800℃×100 0 h长期时效后,-αCr相的数量增加,尺寸长大,γ′相发生了聚集长大,合金中无有害相析出;合金的室温拉伸性能基本稳定,但高温拉伸强度和持久寿命下降;γ′相的聚集长大是致使长期时效后GH648合金高温拉伸强度和持久寿命下降的主要原因。

The structure stability of GH648 alloy aged at 800℃ for 1 000 h was studied. The experimental results showed that the amount and the size of the α-Cr phase increased and γ＇phase aggreated and developed after the long-term aging treatment. There is no deleterious phase formation after long-term aging heat treatment. With the aging time changing up to 1 000 h, the room temperature strength was stabler, and the high temperature strength and the rupture lifetime of GH648 alloy decreased. The decrease is mainly attributed to the aggregation and development of γ＇phase.