(1. 中南大學(xué)材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué)有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 316L奧氏體不銹鋼(簡稱316L鋼)具有優(yōu)良的高溫力學(xué)、耐侵蝕等性能，在航空、核能等領(lǐng)域具有廣泛應(yīng)用。然而，316L鋼在高溫氧化環(huán)境下長期服役時(shí)，易產(chǎn)生開裂、剝落等缺陷而失效。采用熱軋復(fù)合、退火熱處理和原位氧化的方式在316L鋼表面制備了Fe-Al/Al2O3高溫抗氧化涂層，利用XRD、SEM、EDS等手段對試樣的物相組成和組織形貌進(jìn)行了表征，對比研究含有Fe-Al/Al2O3涂層的試樣和316L鋼的高溫氧化行為。結(jié)果表明：316L鋼和純鋁箔經(jīng)熱軋后，復(fù)合板界面的平均結(jié)合強(qiáng)度為54.47 N/mm2；鋁/鋼復(fù)合板經(jīng)不同溫度退火6 h后，發(fā)現(xiàn)750 ℃退火試樣擴(kuò)散層的厚度急劇增加，幾乎占據(jù)全部鋁層；選擇750 ℃退火試樣進(jìn)行1 h的原位氧化，制得了Fe-Al/Al2O3涂層，其截面結(jié)構(gòu)由表及里依次為Al2O3、FeAl2、FeAl、α-Fe(Al)和Fe；原位氧化試樣和316L鋼分別經(jīng)900 ℃空氣氧化72 h后，發(fā)現(xiàn)二者的氧化過程均符合拋物線規(guī)律，而原位氧化試樣氧化質(zhì)量的增加僅為316L鋼的1/11，具有優(yōu)良的高溫抗氧化性能。
關(guān)鍵字: Fe-Al/Al2O3涂層；熱軋復(fù)合；退火熱處理；原位氧化；高溫氧化行為
（1. School of Materials Science and Engineering, Central South
University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials
Science and Engineering, Ministry of Education, Central South University,
Changsha 410083, China）
Abstract:Fe-Al/Al2O3 high-temperature anti-oxidant coating was prepared on the surface of 316L steel by hot-rolling composite, annealing heat treatment and in-situ oxidation. The specimens were characterized by using SEM, EDS and XRD, respectively. Meanwhile, the high-temperature oxidation behavior of the in-situ oxidized specimens containing Fe-Al/Al2O3 coating and 316L steel was investigated comparatively. The results show that the hot-rolled composite plate obtained by holding 316L steel and pure aluminum is well bonded, and the average bond strength of composite plate is obtained as 54.47 N/mm2. Then, the composite plate is held at different temperatures for 6 h for annealing heat treatment. The specimens preferably annealed at 750 ℃ for 6 h with optimum thickness were selected to be oxidized in-situ for 1 h. The Fe-Al/Al2O3 coating is obtained, and its cross-sectional structures in order from the surface to the inside are Al2O3, FeAl2, FeAl, α-Fe(Al) and Fe. When the in-situ oxidized specimen and 316L steel were oxidized at 900 ℃ for 72 h, the oxidation process of them conforms to the parabolic law together. While the oxidation mass gain of the in-situ oxidized specimen is only 1/11 of that of 316L steel, which has excellent high temperature oxidation resistance.
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