Ni-Cr-Co基高温合金704℃和760℃时效组织稳定性被引量：11

Structure stability of Ni-Cr-Co base superalloy aged at 704 ℃ and 760 ℃

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摘要利用热力学计算、SEM、TEM和相分析研究了一种新型Ni Cr Co基高温合金在 70 4℃和 76 0℃长期时效至 2 0 0 0h后的组织变化。结果表明 :该合金标准热处理态和在 70 4℃长期时效后的析出相有MC ,M2 3 C6,M6C和γ′ ,在 76 0℃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 ,M2 3 C6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 76 0℃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 70 4℃长期时效时具有良好的组织稳定性 ,但在 76 0℃时效时组织稳定性较差。 Thermodynamic calculation, SEM, TEM, XRD, phase extraction and chemical analysis were employed to study the structure stability of a new Ni-Cr-Co base superalloy aged at 704 ℃ and 760 ℃ for long time. The results show that the precipitates of alloy standard heat-treated and heat-treated at 704 ℃ and 760 ℃ for time up to 2 000 h are γ′, MC, M 23C 6 and M 6C, and η phases are also formed at grain boundaries and in the matrix of sample heat-treated at 760 ℃ as well. With increase in aging time, the mass fractions of γ′(+η), MC, M 23C 6 and M 6C in all samples have no large changes and their chemical compositions are stable at the same temperature, but the γ′ precipitates grow obviously. The γ′-to-η transformation in sample heat-treated at 760 ℃ takes place with prolonged aging time. The η precipitates form a Widmansttten pattern in samples heat-treated at 760 ℃. The new alloy maintains a better structure stability during prolonged aging at 704 ℃, but a worse structure stability during prolonged aging at 760 ℃.

作者赵双群董建新谢锡善

机构地区北京科技大学高温合金研究室

出处《中国有色金属学报》 EI CAS CSCD 北大核心 2003年第3期565-569,共5页 The Chinese Journal of Nonferrous Metals

关键词 Ni-Cr-Co基高温合金热力学组织稳定性析出相时效 Ni-Cr-Co base superalloy thermodynamic calculation structure stability precipitate

分类号 TG166.7 [金属学及工艺—热处理] TG146.15 [金属学及工艺—金属材料]

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