不同鈍化處理對201不銹鋼腐蝕行為之影響研究

Corrosion Performance of 201 Stainless Steel with Different Passivation Treatments

本研究利用含硝酸的水溶液對高錳含量之201沃斯田系不銹鋼施以鈍化處理，探討不同鈍化處理條件與不銹鋼腐蝕行為的關係，並與304不銹鋼加以比較。鈍化處理分為化學鈍化及電化學鈍化兩種方式，部分鈍化液中含有0.1 M Na2MoO4。鈍化膜在0.1 M HCl水溶液中的耐蝕性質以動電位循環極化法及開路電位衰退法加以評估，並搭配XPS表面成分分析，以釐清不同鈍化溶液及條件對鈍化膜之化學組成的影響。實驗結果顯示，在30 % HNO3鈍化溶液中，化學鈍化時間的增加，及外加電位的提升，皆有助於鈍化膜耐蝕能力的改善。而在鈍化溶液中添加0.1 M Na2MoO4，則會降低201不銹鋼鈍化膜的穩定性。XPS分析結果顯示化學鈍化比電化學鈍化可獲得較高含量的Cr2O3於鈍化膜中，並具較優的耐蝕性。

Passivation and corrosion behavior of high-manganese-containing 201 stainless steel (SS) with different passivation treatments, in comparison with that of 304 SS, were studied. Both chemical passivation and electrochemical passivation were employed, while the passivation solution was HNO3 solution containing Na2MoO4. The corrosion performances of the passive films were evaluated by conducting cyclic potentiodynamic polarization and potential decay analyses in 0.1 M HCl solution. The chemical compositions of the passive film formed under different process were analyzed by X-ray photoelectron spectroscopy (XPS). The experimental results showed that increasing chemical passivation time and applied potential could improve the stability of passive film. However, a less notable breakdown potential was observed if 201 SS was passivated in the electrolyte contained 0.1 M Na2MoO4. Furthermore, XPS results showed that the passive film formed by chemical passivation process had a higher Cr2O3 content than that by electrochemical process, and gave rise to a higher protection against corrosion.