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本文研究了在不同保载时间下GH220合金周期持久断裂行为。采用了二种热处理工艺(等温弯晶工艺和标准直晶工艺)。结果表明,在750,800,850及900℃,保载时间为0—32min及∞持久条件下,二种晶界状态的GH220含金都不符合线性累积损伤规则sum(Δt/t_r)+N_i/N_f=1。一般表现为明显地强化。实验表明,保载时间对GH220合金的周期持久断裂寿命有很大影响。随着保载时间的变化,断裂寿命出现一个最大值。当保载时间小于3min时有弱化的趋势。本文通过TEM,SEM及金相等手段,研究分析了保载时间严重影响GH220合金断裂寿命的微观机制并从位错组态、位错结构及滞弹性等角度解释保载时间影响GH220合金不同的周期持久强化程度。
In this paper, we study the long-term fracture behavior of GH220 alloy under different holding time. Two heat treatment processes are used (Isothermal Bending Process and Standard Straight Process). The results show that GH220 gold content in both grain boundary states does not meet the linear cumulative damage rule sum (Δt / t_r) + N_i / N_f = 1 at 750, 800, 850 and 900 ℃ for 0-32min and ∞ persistence conditions . The general performance is obviously strengthened. Experiments show that the holding time of GH220 alloy long-lasting fracture life have a great impact. As the loading time changes, the fracture life appears a maximum value. When the loading time is less than 3min weakened trend. In this paper, the microscopic mechanism that the loading time seriously affects the fracture life of GH220 alloy has been studied and analyzed by means of TEM, SEM and gold metallography. The different loading mechanisms of GH220 alloy have been explained based on dislocation configuration, dislocation structure and anelasticity Long-lasting cycle of enhancement.