材料與周圍(wei)非電解質(zhi)之間(jian)發(fa)生(sheng)純化學作用而(er)引起的(de)(de)腐(fu)(fu)蝕(shi)損傷稱為化學腐(fu)(fu)蝕(shi)。其(qi)反(fan)應(ying)(ying)(ying)特點是材料表面(mian)的(de)(de)原(yuan)子與非電解質(zhi)中的(de)(de)氧化劑直接發(fa)生(sheng)氧化還原(yuan)反(fan)應(ying)(ying)(ying),腐(fu)(fu)蝕(shi)產物生(sheng)成于發(fa)生(sheng)腐(fu)(fu)蝕(shi)反(fan)應(ying)(ying)(ying)的(de)(de)表面(mian),當它較牢固地覆蓋在(zai)材料表面(mian)時(shi),會(hui)減緩腐(fu)(fu)蝕(shi)的(de)(de)進一(yi)步發(fa)生(sheng)。腐(fu)(fu)蝕(shi)反(fan)應(ying)(ying)(ying)過程中無電流產生(sheng)。

  金(jin)屬(shu)和電(dian)(dian)(dian)解質(zhi)接觸時(shi),由于(yu)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)池作用而(er)引起的(de)(de)(de)金(jin)屬(shu)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)現象稱為電(dian)(dian)(dian)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)。腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)特(te)點在(zai)于(yu),腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)歷程(cheng)(cheng)可(ke)分為兩個相對獨立的(de)(de)(de)并同時(shi)進行(xing)的(de)(de)(de)陽極和陰極過程(cheng)(cheng)。特(te)征(zheng)為受蝕(shi)(shi)(shi)(shi)(shi)(shi)區是(shi)(shi)金(jin)屬(shu)表面的(de)(de)(de)陽極,腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)產(chan)(chan)物(wu)常常產(chan)(chan)生(sheng)(sheng)在(zai)陽極與陰極之間,不能覆蓋(gai)被蝕(shi)(shi)(shi)(shi)(shi)(shi)區域(yu),通常起不到保護作用。電(dian)(dian)(dian)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)和化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)顯著區別是(shi)(shi)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)過程(cheng)(cheng)中有電(dian)(dian)(dian)流產(chan)(chan)生(sheng)(sheng)。對于(yu)大多數工(gong)業部門而(er)言(yan),發生(sheng)(sheng)電(dian)(dian)(dian)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)情況遠多于(yu)發生(sheng)(sheng)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)情況。金(jin)屬(shu)發生(sheng)(sheng)高溫氧(yang)化(hua)(hua)(hua)(hua),表面生(sheng)(sheng)成(cheng)一定厚度(du)的(de)(de)(de)半導(dao)體性質(zhi)的(de)(de)(de)氧(yang)化(hua)(hua)(hua)(hua)膜,既可(ke)以(yi)傳導(dao)電(dian)(dian)(dian)子,也可(ke)以(yi)導(dao)通離子,此時(shi)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)不再是(shi)(shi)單純的(de)(de)(de)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi),而(er)且還包含了(le)電(dian)(dian)(dian)化(hua)(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)(shi)。