Abstract: The test alloy GH706 (/% : 0.034C, 16.l0Cr, 41. 13Ni, 1.64Ti, 2.93Nb, 0.39Al) and modified alloy (/% : 0.027C, 16.30Cr, 1.79Ti, 2.05Nb, 1.21 Al) are melted by a 200 kg vacuum induction furnace and remelted to 150 kg ESR ingot, then homogenizing-treated at 1 180 ℃T for 16 h and forged to Φ15 mm rod and heat-treated at 980 ℃ for 3 h, cooling with 4 K/min to 820 °C for 2 ~ 10 h, air cooling, and at 720℃ for 16 h, furnace cooling. Results show that increasing Ai content and decreasing Nb content in alloy contribute to precipitates of γ′ phase in alloy; precipitation of η phase at grain boundary can be controlled by adjusting the time of secondary heat treatment led to the excellent strength and plasticity combination of alloy, i.e. as alloy has tensile strength level 1 200 MPa the reduction of area of alloy is near to 30%. As the secondary heat treatment process is at 820 ℃ for 2 h, the tensile strength of modified alloy at 700°C is 908 MPa and the reduction of area is up to 54. 8%.

Key words: Alloy GH706, Al-Nb, 700 °C, γ′Phase, η , Phase, Tensile Strength

摘要： 试验的GH706合金(/%:0.034C、16.10Cr、41.13Ni、1.64Ti、2.93Nb、0.39Al)和改进型合金(/%:0.027C、16.30Cr、1.79Ti、2.05Nb、1.21Al)由200 kg真空感应炉熔炼并重熔成150 kg ESR锭,1 180℃ 16 h均匀化处理后锻成Φ15 mm棒材,并经980℃3 h,4 K/min冷至820℃2～10 h,空冷,720℃16 h炉冷热处理。结果表明,提高合金中的Al含量和降低Nb含量可促使γ′相析出;通过调整二级固溶处理的时间可控制η相析出,使合金具有良好的强塑性,在室温抗拉强度TS 1 200 MPa的水平下使断面收缩率接近30%。改进型合金在二级固溶处理为820℃2 h时,700℃抗拉强度为908 MPa,断面收缩率达54.8%。

关键词:  GH706合金, , Al-Nb, 700 °C. γ′相, η  相, 拉伸性能