N18合金板材酸洗工艺试验研究

Study on Pickling Process of N18 Zirconium Alloy Plate

在N18合金板材生产中，酸洗操作中易出现过酸洗以及在酸洗控厚中板材尺寸超差现象，对此进行了对比试验。研究了氢氟酸浓度、酸洗液温度以及硝酸浓度对N18板材酸洗效果的影响，并对酸洗后的板材取样进行了氢含量分析。试验结果表明，酸洗液中氢氟酸起主要腐蚀作用，当浓度约为8％时，酸洗反应较平缓，酸洗液温度上升较慢，板材酸洗效果好；酸洗液温度对酸洗速率有明显影响，为保证酸洗过程可控，酸洗液反应温度应控制在≤40℃；硝酸起控制反应速率和氢含量的作用，硝酸浓度增高，酸洗反应速率降低，40％～50％的硝酸适宜。

When producting N18 zirconium alloy plate, it is easy to find the phenomenon of over pickling and size out-of- tolerance after pickling. According to this situation, the contrast tests is devised by selecting different concentration of HNO3 and HF with different temperature of the pickling is solution. The results of the study show that when concentration of HF is about eight percent, pickling more gentle, the and the acid liquid temperature rises slowly, acid cleaning effect is good. The acid temperature has obvious influence on the rate of acid pickling and the acid temperature should be controlled in no more than 40℃, the reaction rate and hydrogen content is controlled by HNO3. Then the reaction rate of pickling re- duced with the concentration of HNO3 increases, and the 40%--50% HNO3 is appropriate.