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采用浸泡腐蚀、极化曲线和应力腐蚀等方法研究时效对纳米TiC/Ti细化Al-Zn-Mg-Cu合金耐蚀性的影响。结果表明,峰时效态和过时效态细化合金在3.5%的NaCl溶液中浸泡192h,腐蚀速率分别为0.756 5mm/a和0.361 3mm/a。峰时效态化合金在NaCl和NaCl+H_2O_2溶液中的应力断裂时间分别为72.2h和50.1h;过时效态为221.2h和80.8h,过时效态合金抗应力腐蚀性能高于峰时效态的。峰时效添加TiC/Ti细化合金后晶界较宽的PFZ(无沉淀析出带)降低其耐蚀性,过时效态晶界不连续且粗大的η相以及较窄的PFZ使合金耐蚀性提高。
The effect of aging on the corrosion resistance of nano-TiC / Ti Al-Zn-Mg-Cu alloy was studied by immersion corrosion, polarization curve and stress corrosion test. The results show that the peak aged and aged alloys are immersed in 3.5% NaCl solution for 192 h with the corrosion rates of 0.756 mm / a and 0.361 3 mm / a, respectively. The stress rupture time of the peak-aged alloy in NaCl and NaCl + H 2 O 2 solutions were 72.2h and 50.1h respectively, and the over-aged state was 221.2h and 80.8h, respectively. The anti-stress corrosion resistance of the aged alloy was higher than that of the peak-aged state. The results show that the corrosion resistance of PFZ (with no precipitation zone) after the addition of TiC / Ti alloy after peak aging decreases the corrosion resistance. The outdated grain boundary is discontinuous and the coarse η phase and the narrower PFZ make the alloy corrosion resistance improve.