Oxide-dispersion strengthened steels are promising materials for extreme service conditions including nuclear reactors core. In service conditions, nuclear fuel claddings are exposed to the fission gas pressure at temperatures about 700 °C. This paper presents novel results on ODS creep properties from a round robin of inner gas pressure creep test. A gas pressure creep test, simulating fission gas loading, was designed and achieved by four different European teams. Lifetime and specific behavior of ODS steel tube are prospected. Based on a mechanical clamping achieving gas tightness, short length tubes samples are tested by different laboratories. In situ laser measurements exhibit the radial expansion of ODS steel tubes before failure. Post-mortem, geometrical characterizations are performed to determine hoop strains at failure. A consistent creep lifetime is observed by all the teams even with slightly different testing apparatus and clamping systems. Under inner gas pressure, ODS steels exhibit a typical failure by leakage associated to a very small radial expansion. This behavior results from a brutal failure (burst) without evidence of tertiary creep stage. This failure mode of ODS cladding in creep conditions is consistently observed on all samples of the study. Inner gas pressure creep tests were compared, for the first time, by four European laboratories on ODS steel tube. This technique, simulating the fission gas pressure loading, is applied on small and mechanically clamped samples. This technique shows a remarkable consistency between the different laboratories results and demonstrates to be efficient for ODS steel cladding tube qualification. The results show a correlation between the creep properties and the microstructure.

氧化物弥散强化钢是用于极端服务条件（包括核反应堆堆芯）的有前途的材料。在服役条件下，核燃料包壳暴露于温度约为 700 °C 的裂变气体压力下。本文介绍了内部气压蠕变试验循环中 ODS 蠕变特性的新结果。四个不同的欧洲团队设计并完成了模拟裂变气体加载的气压蠕变测试。展望了ODS钢管的使用寿命和特性。基于实现气密性的机械夹紧，短管样品由不同的实验室进行测试。就地激光测量显示了 ODS 钢管在失效前的径向膨胀。验尸后，执行几何特征以确定失效时的箍应变。即使测试设备和夹紧系统略有不同，所有团队都观察到一致的蠕变寿命。在内部气压下，ODS 钢表现出与非常小的径向膨胀相关的泄漏的典型故障。这种行为是由没有三次蠕变阶段证据的残酷失败（爆发）造成的。蠕变条件下 ODS 覆层的这种失效模式在研究的所有样品中都得到一致观察到。四个欧洲实验室首次对 ODS 钢管的内部气压蠕变试验进行了比较。这种模拟裂变气体压力载荷的技术适用于机械夹紧的小型样品。该技术显示了不同实验室结果之间的显着一致性，并证明对 ODS 钢包覆管鉴定是有效的。结果表明蠕变特性和微观结构之间存在相关性。