Influence of NaCl on dechromization of Cu-Cr-Al alloy in H3PO4 solution
(1. State Key Laboratory of Metastable Materials Science and Technology,
Yanshan University, Qinhuangdao 066004, China;
2. Department of Basic Medical, Tangshan Vocational Technology College, Tangshan 063000, China;
3. Department of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China)
Yanshan University, Qinhuangdao 066004, China;
2. Department of Basic Medical, Tangshan Vocational Technology College, Tangshan 063000, China;
3. Department of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China)
Abstract: The dechromization of Cu-Cr-Al alloys was investigated by a static immersing corrosion test. The influence of NaCl on the dechromization was analyzed by electrochemical test, scanning electron microscopy, optical microscopy and X-ray fluorescence spectroscopy. The results show that the dechromization of Cu-Cr-Al alloys will take place in a H3PO4 solution of 11.32 mol/L at 55 ℃. And the corrosion process occurs initially at the interface between Cu and Cr phase, and then extends inward Cr-phase inside. The addition of NaCl into H3PO4 solutions can shorten the dechromization incubation time, decrease the dechromization temperature and concentration of H3PO4 solution, and increase the tendency of dechromization. But, the NaCl scarcely has an effect on the form and structure of chromium depleted-layer.
Key words: dechromization; Cu-Cr-Al alloy; H3PO4 solution; NaCl