700℃以上服役涡轮盘用难变形镍基高温合金热加工研究进展

Research Progress on the Hot Working of Hard-to-Deform Nickel-Based Superalloys for Turbine Disk Served Above 700℃

航空发动机推重比的不断提高对涡轮盘材料的高温服役性能提出了更严苛的要求。服役温度超过700℃的涡轮盘用镍基变形高温合金的合金化程度和γ′相含量极高,使其变形抗力大幅提高、热塑性明显下降、热加工窗口变窄,在热变形过程中很容易发生开裂和组织失稳,给其涡轮盘的制备带来了极大的困难。介绍了这类难变形镍基高温合金的热加工工艺流程、摩擦和绝热温升修正及本构模型和热加工图的构建方法,综述了典型难变形镍基高温合金Rene65、U720Li、ЭК151、ЭЛ975、TMW的热变形行为研究进展。展望了这类变形高温合金的研究方向,为其热加工工艺优化提供一定的参考。

The increasing thrust-weight ratio of aero-engines puts forward more stringent requirements for the high-temperature service performance of turbine disk alloys.The alloying degree andγ′phase content of nickel-based wrought superalloys used in turbine disks with a service temperature of higher than 700℃are extremely high,which significantly increases the deformation resistance,reduces the thermoplasticity and narrows the hot working window.Hence,cracking and structural instability are easy to occur during the hot deformation.This paper has introduced the hot working process of such hard-to-deform superalloys,corrections of friction and adiabatic heating effect,and construction methods of the constitutive model and processing map.Besides,the research progress on hot deformation behaviors of the typical hard-to-deform superalloys,including Rene65,U720Li,ЭК151,ЭЛ975 and TMW has been reviewed.The future research direction of such alloys has been prospected,which can provide certain reference for optimization of the hot working process.