( 東北大學(xué) 機(jī)械工程與自動(dòng)化學(xué)院， 沈陽 110004)
摘 要: 研究了鎳基變形高溫合金GH4049， 在實(shí)際工作溫度范圍700~900 ℃， 應(yīng)力137~600 MPa下的高溫拉伸蠕變行為， 得到了蠕變后的高溫應(yīng)變恢復(fù)曲線。提出了應(yīng)用參數(shù)優(yōu)化估計(jì)的方法， 在較大溫度及應(yīng)力范圍內(nèi)， 計(jì)算穩(wěn)態(tài)蠕變率的宏觀唯象公式中的各參數(shù)， 并用ZA27和GH4049合金的實(shí)驗(yàn)數(shù)據(jù)驗(yàn)證了該方法的可行性。 GH4049合金各溫度下的穩(wěn)態(tài)蠕變速率與所施加的應(yīng)力，在雙對(duì)數(shù)坐標(biāo)系下呈線性關(guān)系， 應(yīng)力指數(shù)平均值為7.685 1， 平均穩(wěn)態(tài)蠕變激活能為543.6 kJ/mol。
關(guān)鍵字: GH4049合金；蠕變行為； 穩(wěn)態(tài)蠕變速率； 應(yīng)變恢復(fù)； 穩(wěn)態(tài)蠕變激活能 ； 參數(shù)優(yōu)化估計(jì)
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
