【摘要】 采用粉末冶金热等静压工艺制备了氧化物弥散强化FeCrAl合金，通过擦拭试验模拟实际生产、运输、安装及使用等过程中表面轻微触碰对预氧化后氧化层表面的轻微破坏，结合扫描电镜和透射电镜研究初始氧化层表面完整性对后续高温氧化行为的影响。结果表明：在650℃下暴露于空气中预氧化10 h后，合金表面形成针状纳米级Fe-O型氧化物和近球形的纳米级Fe-Cr-O型颗粒及微米级Y-Zr-O型颗粒。对预氧化后的合金表面进行擦拭，针状Fe-O型氧化物因粘附性较差易被擦除；近球形Fe-Cr-O颗粒和Y-Zr-O颗粒因粘附性较好难以擦除。650℃×10 h预氧化后直接在1000℃氧化，氧化层表面以较连续致密的Al-O型氧化物为主，含部分直径2～3μm的近球形Fe-O型氧化物颗粒；650℃×10 h预氧化后擦拭合金表面再在1000℃氧化，氧化层表面为疏松的片状Al-O型氧化物，近球形Fe-O型氧化物颗粒数量减少且尺寸变小。1000℃氧化200 h后，未经擦拭合金的表面氧化层为厚度约2.47μm的连续致密Al-O型氧化物；而擦拭合金的表面氧化层包含厚度约1.17μm的上层疏松片状Al-O型氧化物和厚度约1.31μm的下层连续致密Al-O型氧化物；两种条件下内氧化深度都在51.5μm左右，表明表面轻微触碰不会显著影响预氧化合金的抗高温氧化性能。更多还原

【Abstract】 Oxide dispersion strengthened(ODS) FeCrAl alloy was fabricated via the powder metallurgy hot isostatic pressing process. A wiping test was conducted to simulate the slight damage to the pre-oxidized surface oxide layer caused by minor contact during actual production, transportation, installation, and service. The effect of initial oxide layer integrity on the subsequent high-temperature oxidation behavior was investigated using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results show that after pre-oxidation at 650 ℃ in air for 10 h, the alloy surface forms needle-like nano-sized Fe-O oxides, nearly spherical nano-sized Fe-Cr-O particles, and micron-sized Y-Zr-O particles. When the pre-oxidized surface is wiped, the needle-like Fe-O oxides are easily removed due to their poor adhesion, whereas the nearly spherical Fe-Cr-O particles and Y-Zr-O particles are remained intact owing to their good adhesion. Direct oxidation at 1000 ℃ after pre-oxidation at 650 ℃ for 10 h results in a surface oxide layer dominated by a relatively continuous and dense Al-O oxide, with some nearly spherical Fe-O oxide particles(2-3 μm in diameter). In contrast, oxidation at 1000 ℃ following surface wiping after pre-oxidation lesds to a loose flaky Al-O oxide layer, where the Fe-O particles exhibited reduced quantity and smaller size. After oxidation at 1000 ℃ for 200 h, the surface oxide layer of the unwiped alloy is consisted of a continuous and dense Al-O oxide with a thickness of approximately 2.47 μm. For the wiped alloy, the oxide layer is consisted of an upper loose flaky Al-O oxide layer(about 1.17 μm thickness) and a lower continuous dense Al-O oxide layer(≈1.31 μm thickness). The internal oxidation depth is approximately 51.5 μm under both conditions, indicating that slight surface contact does not significantly impair the high-temperature oxidation resistance of the pre-oxidized alloy.更多还原