( 东北大学 机械工程与自动化学院， 沈阳 110004)
摘 要: 研究了镍基变形高温合金GH4049， 在实际工作温度范围700~900 ℃， 应力137~600 MPa下的高温拉伸蠕变行为， 得到了蠕变后的高温应变恢复曲线。提出了应用参数优化估计的方法， 在较大温度及应力范围内， 计算稳态蠕变率的宏观唯象公式中的各参数， 并用ZA27和GH4049合金的实验数据验证了该方法的可行性。 GH4049合金各温度下的稳态蠕变速率与所施加的应力，在双对数坐标系下呈线性关系， 应力指数平均值为7.685 1， 平均稳态蠕变激活能为543.6 kJ/mol。
关键字: GH4049合金；蠕变行为； 稳态蠕变速率； 应变恢复； 稳态蠕变激活能 ； 参数优化估计
at high temperature
（ School of Mechanical Engineering and Automation，
Northeastern University， Shenyang 110004, China）
Abstract: The high temperature tensile creep behavior including high temperature strain recovery after creep was investigated for GH4049 nickel-based wrought superalloy. The selected temperature range was 700-900 ℃ in terms of the actual service temperature and the applied stress range was 137-600 MPa. An optimization method of parameter estimate was presented to calculate the constants in the phenomenological equation of steady-state creep rate in a larger temperature and stress range and then the feasibility of the optimization method was validated for ZA27 alloy and GH4049 superalloy. For GH4049 superalloy, there is a linear relationship between the steady-state creep rate and the applied stress in the logarithm coordinate system at all studied temperatures. The mean stress exponent is 7.685 1 and the steady-state creep activation energy is 543.6 kJ/mol, which is much greater than the activation energy for the atomic self-diffusion of Ni.
Key words: GH4049 nickel-based superalloy; tension creep behavior; steady-state creep rate; strain recovery; steady-state creep activation energy; optimization method of parameter estimate
