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在1173—1323K温度范围内研究了Ni-20Cr合金蠕变行为与位错亚结构的关系.在蠕变初期出现蠕变速率几乎不变的亚稳态阶段.电镜观察表明,亚稳态蠕变和未形成亚晶的均匀位错结构相对应.亚稳态到稳态的蠕变速率连续降低的过渡阶段是蠕变中形成的亚晶界逐渐取代晶界起位错攀移相消位置的结果. 提出了控制稳态蠕变速率的亚结构参数是亚晶界位错网目尺寸,蠕变速率可用ε=αρtbV_c/h表示.根据位错在晶界或亚晶界上攀移相消控制的蠕变机制讨论了固溶碳和晶界碳化物对蠕变行为的影响.
The relationship between the creep behavior and the dislocation substructure of Ni-20Cr alloy was investigated in the temperature range of 1173-1323 K. The metastable phase with almost constant creep rate appeared at the initial stage of creep.The results of TEM showed that the metastable creep Which corresponds to the uniform dislocation structure without subgrain.The transitional phase with continuous decreasing of the metastable steady-state creep rate is that the subgrain boundary formed in the creep gradually replaces the dislocation offset position in the grain boundary Results The sub-structure parameters controlling the steady-state creep rate are proposed as sub-intergranular dislocation mesh size, and the creep rate can be expressed as ε = αρtbV_c / h. According to the displacement descending on the grain boundary or subgrain boundary The controlled creep mechanism discusses the effect of solid solution carbon and grain boundary carbides on creep behavior.