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将Zr-Sn-Nb合金板坯分别进行610,650,700,800℃热轧、冷轧、中间退火及成品退火处理,然后把它们放入高压釜中分别进行360℃/300d,500℃/500h的腐蚀试验,用扫描电镜研究试样的显微组织和第二相粒子的分布与尺寸。结果表明,610,650℃处理的样品与700,800℃处理的样品比较,前者具有较小的腐蚀增重,360℃/300d时,腐蚀增重比后者减少10%以上,说明其有相对较好的腐蚀性能。通过对4种样品组织中的第二相的统计分析发现,610,650℃试样与700,800℃的组织相比,610,650℃试样组织中第二相尺寸小于50nm的较多可占总数的65%以上,且样品中析出的第二相粒子均匀细小,这就是其腐蚀性能相对较好的原因。总体上,随轧制温度的升高小于50nm的第二相粒子的百分含量减少,第二相粒子长大,导致腐蚀性能恶化。
The Zr-Sn-Nb alloy slabs were hot-rolled, cold-rolled, intermediate-annealed and finished-annealed at 610, 650, 700 and 800 ° C, respectively, and then put into autoclaves to undergo corrosion tests at 360 ° C / 300d and 500 ° C / Scanning electron microscopy study of the microstructure and distribution of second phase particles and size. The results show that the former has smaller corrosion weight gain than the one treated at 700 and 800 ℃, and the corrosion weight gain is reduced by more than 10% at 360 ℃ / 300d, indicating that it has relatively good corrosion performance. According to the statistical analysis of the second phase of the four kinds of samples, it is found that more than 65% of the total number of the second phase in the 610,650 ° C sample with the second phase size less than 50 nm in the sample structure of 610,650 ° C is 700,800 ° C , And the sample precipitated second phase particles uniform and small, which is the reason for its relatively good corrosion performance. In general, the percentage of the second-phase particles smaller than 50 nm as the rolling temperature increases decreases and the second-phase particles grow, resulting in deterioration of the corrosion performance.