Transition of zirconium alloys during uniform corrosion is not expected but inevitable, since it accelerates the degradation of corrosion property. Up to now, proposed transition mechanisms have not clearly illustrated the critical behavior of interfacial t-ZrO₂ and other oxide features under the critical transition condition. Therefore, study on the under-transition sample was carried out. Microscopically, the monoclinic stress increases after transition, strongly supporting the occurrence of transformation from t-ZrO₂ to m-ZrO₂. A sudden stress decrease in t-ZrO₂ occurs in pre-transition region of the under-transition sample. This decrease might be attributed to formation of permeable paths which induce consumption of interfacial oxygen vacancies. This critical behavior possibly destabilizes the grown t-ZrO₂ grains. And the post-transition regions will propagate after t-ZrO₂ transformation. The transition region in the oxide consists of lateral cracks propagated transgranularly and large numbers of interconnected pores, both of which may originate from t-ZrO₂ transformation. Current works suggest that three critical behaviors of t-ZrO₂ induce oxide fracture and corrosion transition. The growth nature and evolution mechanism of t-ZrO₂ are further illustrated. Even though t-ZrO₂ layer similarly evolve as the ZrO suboxide layer, the unstable nature of t-ZrO₂ indicates that it is severely affected by grain size, stress value and chemical composition.

锆合金在均匀腐蚀过程中的转变是无法预料的，​​但不可避免，因为它会加速腐蚀性能的下降。到目前为止，提出的过渡机制尚未清楚地说明在临界过渡条件下界面t-ZrO ₂和其他氧化物特征的临界行为。因此，对过渡不足样品进行了研究。微观上，单斜应力在转变后增加，有力地支持了从t-ZrO ₂到m-ZrO ₂的转变。t-ZrO _2的应力突然降低发生在过渡不足样品的过渡前区域。该减少可能归因于渗透性路径的形成，其导致界面氧空位的消耗。这种临界行为可能会使生长的t-ZrO ₂晶粒不稳定。并且t-ZrO ₂转化后，过渡后区域将传播。氧化物中的过渡区由横向裂纹和大量相互连通的孔组成，这两个裂纹都可能源自t-ZrO ₂转变。当前的工作表明，t-ZrO _2的三种临界行为会引起氧化物断裂和腐蚀转变。t-ZrO ₂的生长性质及其演化机理进一步说明。即使t-ZrO ₂层与ZrO低氧层相似地发展，t-ZrO ₂的不稳定性质也表明它受到晶粒尺寸，应力值和化学成分的严重影响。