材(cai)料(liao)與(yu)周圍非電解(jie)質之間(jian)發(fa)(fa)生純化學(xue)作用而引起的(de)(de)腐(fu)(fu)蝕(shi)損傷稱為化學(xue)腐(fu)(fu)蝕(shi)。其反(fan)應特點是材(cai)料(liao)表(biao)面(mian)(mian)的(de)(de)原子與(yu)非電解(jie)質中的(de)(de)氧化劑直接發(fa)(fa)生氧化還(huan)原反(fan)應,腐(fu)(fu)蝕(shi)產(chan)物生成于發(fa)(fa)生腐(fu)(fu)蝕(shi)反(fan)應的(de)(de)表(biao)面(mian)(mian),當它較(jiao)牢固地覆(fu)蓋在(zai)材(cai)料(liao)表(biao)面(mian)(mian)時(shi),會減緩腐(fu)(fu)蝕(shi)的(de)(de)進(jin)一步發(fa)(fa)生。腐(fu)(fu)蝕(shi)反(fan)應過(guo)程中無電流產(chan)生。

  金(jin)(jin)屬(shu)和電(dian)(dian)(dian)(dian)解質接觸時,由于腐(fu)(fu)(fu)蝕(shi)(shi)(shi)電(dian)(dian)(dian)(dian)池(chi)作用(yong)而(er)(er)(er)引(yin)起(qi)的(de)金(jin)(jin)屬(shu)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)現象稱為(wei)(wei)電(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)。腐(fu)(fu)(fu)蝕(shi)(shi)(shi)的(de)特點在于,腐(fu)(fu)(fu)蝕(shi)(shi)(shi)歷程可分為(wei)(wei)兩個相對(dui)獨立的(de)并同時進行的(de)陽(yang)(yang)極(ji)和陰(yin)極(ji)過程。特征為(wei)(wei)受蝕(shi)(shi)(shi)區是金(jin)(jin)屬(shu)表(biao)面的(de)陽(yang)(yang)極(ji),腐(fu)(fu)(fu)蝕(shi)(shi)(shi)產(chan)物常(chang)(chang)(chang)常(chang)(chang)(chang)產(chan)生在陽(yang)(yang)極(ji)與(yu)陰(yin)極(ji)之間,不(bu)(bu)能覆蓋被蝕(shi)(shi)(shi)區域,通常(chang)(chang)(chang)起(qi)不(bu)(bu)到保護作用(yong)。電(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)和化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)的(de)顯著區別是腐(fu)(fu)(fu)蝕(shi)(shi)(shi)過程中有(you)電(dian)(dian)(dian)(dian)流產(chan)生。對(dui)于大多(duo)數工業(ye)部門而(er)(er)(er)言,發(fa)生電(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)的(de)情況遠(yuan)多(duo)于發(fa)生化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)的(de)情況。金(jin)(jin)屬(shu)發(fa)生高溫氧(yang)(yang)化(hua)(hua),表(biao)面生成(cheng)一定(ding)厚度(du)的(de)半導體性(xing)質的(de)氧(yang)(yang)化(hua)(hua)膜,既可以傳(chuan)導電(dian)(dian)(dian)(dian)子,也可以導通離子,此時腐(fu)(fu)(fu)蝕(shi)(shi)(shi)不(bu)(bu)再是單純的(de)化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi),而(er)(er)(er)且還包含了電(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)。