【摘要】 对Zr-Sn-Nb合金和Zr-4合金包壳管进行了600～1200℃高温蒸汽氧化试验，对比研究了不同温度、不同时间的氧化动力学及其对显微组织、氧化膜厚度的影响。结果表明：Zr-Sn-Nb合金和Zr-4合金在高温蒸汽中的氧化规律基本一致，氧化速率主要与温度有关。经950～1200℃蒸汽氧化5000 s后，Zr-4合金的氧化增量明显高于Zr-Sn-Nb合金。氧化温度较低时，合金基体均为单一的α相，随着氧化温度的升高，基体中形成脆性的α-Zr(O)相，经1050℃蒸汽氧化2500 s后，Zr-Sn-Nb合金中生成的脆性α-Zr(O)相明显少于Zr-4合金。经较高温度氧化后，Zr-Sn-Nb合金氧化膜依然致密而完整，而Zr-4合金氧化膜开始出现疏松和孔洞。在950～1200℃高温蒸汽中，Zr-Sn-Nb合金展现出了更好的抗高温氧化性能。更多还原

【Abstract】 High temperature steam oxidation tests between 600-1200 ℃ for Zr-Sn-Nb and Zr-4 alloy cladding tubes were conducted to study the effect of oxidation temperature and time on the oxidation kinetics, microstructure and oxidized film thickness. The results show that the oxidation laws of the Zr-Sn-Nb and Zr-4 alloy in high temperature steam are the same, and the oxidation rate is mainly related to temperature. The oxidation mass gain of the Zr-4 alloy is obviously higher than that of the Zr-Sn-Nb alloy after oxidation between 950-1200 ℃ for 5000 s. When the oxidation temperature is low, the matrix of the alloys is single α phase. With the increase of oxidation temperature, brittle α-Zr(O) phase is formed in the matrix. When steam oxidation at 1050 ℃ for 2500 s, the brittle α-Zr(O) phase formed in the Zr-Sn-Nb alloy is significantly less than that in the Zr-4 alloy. When the oxidation temperature is high, the oxide film of the Zr-Sn-Nb alloy is still compact and intact, while the oxide film of the Zr-4 alloy begins to appear loose and porous. At 950-1200 ℃, Zr-Sn-Nb alloy shows better high temperature oxidation resistance.更多还原