利用热力学计算、SEM、TEM和相分析研究了一种新型Ni-Cr-Co基高温合金在704℃和760℃长期时效至2000h后的组织变化.结果表明: 该合金标准热处理态和在704℃长期时效后的析出相有MC, M23C6, M6C和γ′, 在760℃长期时效后还析出了η相.随时效时间增加, γ′(+η)及碳化物MC, M23C6和M6C的含量变化很小, 化学组成稳定, 但γ′相粗化明显.该合金在760℃时效时, η相的析出随时效时间的增加而加剧, 并且呈魏氏体分布.新合金在704℃长期时效时具有良好的组织稳定性, 但在760℃时效时组织稳定性较差.
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