材料與(yu)周圍(wei)非電解質(zhi)(zhi)之間發生(sheng)純化(hua)(hua)學作用而引起的腐蝕(shi)損(sun)傷稱(cheng)為化(hua)(hua)學腐蝕(shi)。其反(fan)應(ying)(ying)特(te)點(dian)是(shi)材料表(biao)面(mian)的原子與(yu)非電解質(zhi)(zhi)中(zhong)(zhong)的氧(yang)化(hua)(hua)劑直接發生(sheng)氧(yang)化(hua)(hua)還原反(fan)應(ying)(ying),腐蝕(shi)產物生(sheng)成于發生(sheng)腐蝕(shi)反(fan)應(ying)(ying)的表(biao)面(mian),當它較牢固地(di)覆蓋在材料表(biao)面(mian)時,會減緩腐蝕(shi)的進一步發生(sheng)。腐蝕(shi)反(fan)應(ying)(ying)過(guo)程(cheng)中(zhong)(zhong)無電流產生(sheng)。

  金(jin)(jin)屬和電(dian)(dian)解(jie)質接觸(chu)時(shi),由(you)于腐(fu)(fu)蝕(shi)(shi)電(dian)(dian)池作用而引起(qi)的(de)(de)金(jin)(jin)屬腐(fu)(fu)蝕(shi)(shi)現象稱為電(dian)(dian)化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)。腐(fu)(fu)蝕(shi)(shi)的(de)(de)特(te)點在于,腐(fu)(fu)蝕(shi)(shi)歷程(cheng)可(ke)(ke)分為兩個相對(dui)獨立的(de)(de)并同時(shi)進行的(de)(de)陽極和陰極過(guo)程(cheng)。特(te)征(zheng)為受(shou)蝕(shi)(shi)區是金(jin)(jin)屬表(biao)面(mian)的(de)(de)陽極,腐(fu)(fu)蝕(shi)(shi)產物常常產生在陽極與陰極之間(jian),不能(neng)覆蓋被蝕(shi)(shi)區域,通(tong)常起(qi)不到保護作用。電(dian)(dian)化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)和化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)的(de)(de)顯著(zhu)區別是腐(fu)(fu)蝕(shi)(shi)過(guo)程(cheng)中(zhong)有電(dian)(dian)流(liu)產生。對(dui)于大多數工(gong)業部門而言,發生電(dian)(dian)化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)的(de)(de)情況(kuang)遠多于發生化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)的(de)(de)情況(kuang)。金(jin)(jin)屬發生高溫氧化(hua)(hua)(hua),表(biao)面(mian)生成(cheng)一定厚度的(de)(de)半導體性質的(de)(de)氧化(hua)(hua)(hua)膜,既可(ke)(ke)以傳導電(dian)(dian)子(zi),也(ye)可(ke)(ke)以導通(tong)離子(zi),此時(shi)腐(fu)(fu)蝕(shi)(shi)不再是單純的(de)(de)化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi),而且還包(bao)含了(le)電(dian)(dian)化(hua)(hua)(hua)學腐(fu)(fu)蝕(shi)(shi)。