對黃(huang)銅(tong)脫鋅腐蝕的機(ji)(ji)理(li),國內(nei)外都(dou)做了一(yi)些研究,提出了各(ge)種研究結論,但(dan)目前還(huan)不十(shi)分完(wan)善,主要(yao)理(li)論有優先溶(rong)解(jie)和(he)溶(rong)解(jie)-再(zai)沉積機(ji)(ji)制(zhi)、雙空位(wei)機(ji)(ji)制(zhi)和(he)滲流機(ji)(ji)制(zhi)。接下就(jiu)讓(rang)我們來簡單(dan)的介紹一(yi)下這些機(ji)(ji)制(zhi)。         

 1. 優先(xian)溶解和(he)溶解一再(zai)沉積機制，優先溶(rong)(rong)(rong)解機制(zhi)認為,黃(huang)銅(tong)腐(fu)蝕過程中,合金表(biao)面(mian)的(de)(de)鋅(xin)(xin)(xin)(xin)從(cong)黃(huang)銅(tong)中優先溶(rong)(rong)(rong)解,然后合金內(nei)部的(de)(de)鋅(xin)(xin)(xin)(xin)通過空位擴(kuo)散繼續溶(rong)(rong)(rong)解,電位較(jiao)正的(de)(de)銅(tong)被(bei)遺留下來,呈疏松(song)狀的(de)(de)銅(tong)層。但這種理論(lun)難以說明脫鋅(xin)(xin)(xin)(xin)造成的(de)(de)脆性(xing)(xing)(xing)開裂深(shen)度與鋅(xin)(xin)(xin)(xin)在室溫下擴(kuo)散系數太低之間的(de)(de)矛盾(dun)。而在黃(huang)銅(tong)表(biao)面(mian)與溶(rong)(rong)(rong)液接觸處發生了鋅(xin)(xin)(xin)(xin)選(xuan)擇性(xing)(xing)(xing)溶(rong)(rong)(rong)解,被(bei)腐(fu)蝕的(de)(de)鋅(xin)(xin)(xin)(xin)由合金晶格上鋅(xin)(xin)(xin)(xin)原子的(de)(de)擴(kuo)散所(suo)補償,鋅(xin)(xin)(xin)(xin)在活性(xing)(xing)(xing)脫鋅(xin)(xin)(xin)(xin)前(qian)沿被(bei)選(xuan)擇性(xing)(xing)(xing)侵蝕,這個(ge)前(qian)沿不(bu)斷地向(xiang)(xiang)內(nei)部移動。按照作者的(de)(de)觀點,脫鋅(xin)(xin)(xin)(xin)相只是(shi)在初始黃(huang)銅(tong)母體的(de)(de)骨架結構中出現,它容許鋅(xin)(xin)(xin)(xin)離子自由向(xiang)(xiang)外(wai)擴(kuo)散,黃(huang)銅(tong)的(de)(de)脫鋅(xin)(xin)(xin)(xin)阻力依賴于鋅(xin)(xin)(xin)(xin)外(wai)層電子離開鋅(xin)(xin)(xin)(xin)原子的(de)(de)難易程度。    

 2. 溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)-再沉積機制(zhi)認(ren)為,黃銅(tong)(tong)(tong)表(biao)(biao)面上的(de)(de)(de)鋅(xin)和銅(tong)(tong)(tong)一起(qi)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie),鋅(xin)留在溶(rong)(rong)(rong)(rong)(rong)液中(zhong)，而(er)銅(tong)(tong)(tong)在靠近溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)處的(de)(de)(de)表(biao)(biao)面上迅速(su)(su)(su)析出而(er)重(zhong)新(xin)沉積在基(ji)體上,但(dan)這(zhe)種機制(zhi)無(wu)法圓(yuan)滿(man)地解(jie)(jie)(jie)(jie)釋銅(tong)(tong)(tong)不可(ke)能溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)時(shi)(shi)的(de)(de)(de)脫(tuo)(tuo)鋅(xin)現象。因為鋅(xin)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)的(de)(de)(de)電(dian)位遠低于(yu)銅(tong)(tong)(tong)的(de)(de)(de)陽極溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)電(dian)位,因此(ci)銅(tong)(tong)(tong)和鋅(xin)不可(ke)能在任何情況下發生同時(shi)(shi)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)的(de)(de)(de)現象。在硫酸(suan)(suan)中(zhong)進行了研(yan)究,在最初(chu)階段由于(yu)建立了(Cu-Zn)原電(dian)池,鋅(xin)在溶(rong)(rong)(rong)(rong)(rong)液中(zhong)優先溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie),但(dan)當多孔的(de)(de)(de)銅(tong)(tong)(tong)-氧化銅(tong)(tong)(tong)膜在電(dian)極表(biao)(biao)面形成時(shi)(shi),脫(tuo)(tuo)鋅(xin)速(su)(su)(su)度下降(jiang),銅(tong)(tong)(tong)、鋅(xin)同時(shi)(shi)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)。這(zhe)時(shi)(shi)鋅(xin)的(de)(de)(de)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)速(su)(su)(su)度受(shou)通過晶格空位的(de)(de)(de)擴(kuo)散速(su)(su)(su)度所控制(zhi),在這(zhe)個階段銅(tong)(tong)(tong)的(de)(de)(de)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)速(su)(su)(su)度因為CuO膜的(de)(de)(de)形成而(er)減少(shao),這(zhe)決定性(xing)地位取決于(yu)腐蝕(shi)(shi)條件(jian),比如在稀鹽酸(suan)(suan)中(zhong)會(hui)發生鋅(xin)的(de)(de)(de)選擇(ze)性(xing)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie),而(er)在濃度較高(gao)的(de)(de)(de)鹽酸(suan)(suan)或海水(shui)中(zhong)則發生銅(tong)(tong)(tong)重(zhong)新(xin)析出的(de)(de)(de)脫(tuo)(tuo)鋅(xin)腐蝕(shi)(shi)。此(ci)外,脫(tuo)(tuo)鋅(xin)機制(zhi)還受(shou)到溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie)溫度、浸泡周期長短的(de)(de)(de)影響。銅(tong)(tong)(tong)和鋅(xin)是(shi)否同時(shi)(shi)溶(rong)(rong)(rong)(rong)(rong)解(jie)(jie)(jie)(jie),可(ke)以將它們(men)的(de)(de)(de)電(dian)位-pH圖重(zhong)疊后預(yu)測。        

 而防止黃(huang)銅(tong)(tong)脫(tuo)鋅腐(fu)蝕的方(fang)法，主要(yao)可以從冶金(jin)(jin)方(fang)面入手(shou),其次也可從改(gai)善環(huan)境(jing)方(fang)面考慮。改(gai)善腐(fu)蝕環(huan)境(jing)，則(ze)可以采用陰極保護(hu)、添加緩蝕劑、降低介質浸蝕性等,不過由于受工況條件的限制,并不能(neng)完全(quan)抑制黃(huang)銅(tong)(tong)的脫(tuo)鋅。根治的方(fang)法，則(ze)是通過冶金(jin)(jin)化方(fang)法提高黃(huang)銅(tong)(tong)自身的抗脫(tuo)鋅能(neng)力,這才是杜絕黃(huang)銅(tong)(tong)脫(tuo)鋅腐(fu)蝕的發生絕對(dui)好方(fang)法。