【摘要】：通過(guò)對(duì)一種等溫鍛造GH4169鎳基合金進(jìn)行直接時(shí)效處理,蠕變性能測(cè)試及組織形貌觀察,研究了該合金的組織結(jié)構(gòu)與蠕變行為。結(jié)果表明,GH4169合金的組織結(jié)構(gòu)由γ基體,γ′相、γ″相和δ相組成,且各相之間保持共格界面。測(cè)定出合金在660℃/700MPa條件下的蠕變壽命為123h。合金在680℃/700MPa的蠕變壽命為39h,在實(shí)驗(yàn)溫度和應(yīng)力范圍內(nèi),計(jì)算出直接時(shí)效合金的蠕變激活能為588.0kJ/mol。合金在蠕變期間的變形機(jī)制是位錯(cuò)滑移和孿晶變形,其中,沿晶界析出的粒狀碳化物,可抑制晶界滑移,是使合金具有較好蠕變抗力的主要原因。隨蠕變進(jìn)行,開(kāi)動(dòng)的滑移系中位錯(cuò)運(yùn)動(dòng)至晶界受阻,并塞積于該區(qū)域引起應(yīng)力集中,當(dāng)應(yīng)力集中值大于晶界的結(jié)合強(qiáng)度時(shí),可促使其在與應(yīng)力軸垂直的晶界處發(fā)生裂紋的萌生與擴(kuò)展,直至斷裂,是合金在蠕變期間的斷裂機(jī)制。
[Abstract]:The microstructure and creep behavior of an isothermal forged GH4169 nickel-base alloy were studied by direct aging treatment, creep test and microstructure observation. The results show that the microstructure of GH4169 alloy is composed of 緯 matrix, 緯 'phase, 緯 "phase and 未 phase, and the coherent interface between the phases is maintained. The creep life of the alloy at 660 鈩，

本文編號(hào)：2292099