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研究锌合金腐蚀问题大都采用在95℃水蒸气中暴露240h的加速“老化”方法,该方法试验周期长。本研究采用在118℃水蒸气中暴露51h的加速腐蚀方法,试验时间短,试验周期可缩短近五分之四,而且操作方便,重现性好。利用这种方法研究Zn-Al二元合金耐蚀性能发现,共晶合金和含19％Al左右的合金耐蚀性能最差。在35％Al左右的合金还存在有低耐蚀性能成分区,这是本研究首次发现的。研究Zn-27％Al合金表明,单独加1％左右的铜或加0.03—0.05％的镁,能显著地改善合金耐蚀性能;分别添加0.005—1％Ti或0.001—0.5％的混合稀土金属或单元素镧,对合金耐蚀性能无明显影响;研究杂质铅、锡、镉的影响指出,无论是铸造状态条件下的还是均匀化处理后的,都是锡危害性最大,铅次之,镉居第三位。对Zn-27％Al合金进行不同制度热处理时发现,当合金处于淬火状态时,因相变对合金腐蚀的促进作用具有最低的耐蚀性,而均匀化处理及淬火时效的稳定化处理对改善 Zn-27％Al合金耐蚀性能作用不明显。
Study of corrosion of zinc alloy are mostly used in the 95 ℃ water vapor exposure 240h accelerated “aging” method, the test cycle length. In this study, the accelerated corrosion method exposed to water vapor at 118 ℃ for 51h was adopted. The test time was short, and the test period was shortened by nearly four-fifths, and the operation was convenient and the reproducibility was good. Using this method to study the corrosion resistance of Zn-Al binary alloys found that eutectic alloys and alloys containing about 19% Al corrosion resistance of the worst. In the alloy of about 35% Al, there is also a region of low corrosion resistance composition, which is the first time this study was discovered. The study of Zn-27% Al alloy shows that adding about 1% Cu or 0.03-0.05% Mg alone can significantly improve the corrosion resistance of the alloy; adding 0.005-1% Ti or 0.001-0.5% mixed rare earth metal Or single-element lanthanum has no obvious effect on the corrosion resistance of the alloy. Studying the influence of lead, tin and cadmium impurities, it is pointed out that the tin is the most hazardous and the lead is inferior in the condition of casting or homogenization, Cadmium ranks third. When Zn-27% Al alloy is heat treated in different regimes, it is found that when the alloy is in quenched state, the corrosion resistance is promoted by the phase change to the alloy corrosion, and the homogenization and quenching aging stabilizing treatment is better The corrosion resistance of Zn-27% Al alloy is not obvious.