1. 補鍍硬鉻(ge)的適應性


a. 由于電(dian)網(wang)停(ting)電(dian),鍍鉻中(zhong)途斷電(dian),來電(dian)后(hou)需要繼續補鍍鉻以達到規定(ding)厚(hou)度者。


b. 由于工作上的失誤,不(bu)銹鋼表面局部鍍上硬鉻而另一部分尚未鍍上鉻,需要在已鍍硬鉻表面和未鍍上硬鉻的不銹鋼表面上繼續鍍硬鉻至規定厚度者。


c. 鍍完(wan)硬(ying)鉻(ge)后鉻(ge)層(ceng)厚度未達(da)到規定尺(chi)寸,或在磨光硬(ying)鉻(ge)層(ceng)后產品尺(chi)寸未達(da)規定要求者。


 以上諸種(zhong)情況,可(ke)以不采用退除鉻(ge)層重鍍(du)(du)鉻(ge),而可(ke)實施在表面上補鍍(du)(du)硬(ying)鉻(ge)。



2. 工藝分析


  鉻(ge)上補鍍(du)(du)鉻(ge)和(he)不(bu)銹(xiu)(xiu)鋼(gang)(gang)鍍(du)(du)鉻(ge)的(de)表(biao)面(mian)(mian)(mian)(mian)活(huo)化(hua)(hua)處(chu)理不(bu)盡相同,鉻(ge)上鍍(du)(du)鉻(ge)是要將鍍(du)(du)鉻(ge)表(biao)面(mian)(mian)(mian)(mian)作為(wei)陽極進行(xing)腐(fu)蝕一(yi)定時間,以形(xing)成微觀粗糙的(de)活(huo)化(hua)(hua)表(biao)面(mian)(mian)(mian)(mian),再將鍍(du)(du)件(jian)轉換成陰(yin)極,再階梯遞升電(dian)(dian)流到工藝規范的(de)電(dian)(dian)流進行(xing)鍍(du)(du)鉻(ge)。不(bu)銹(xiu)(xiu)鋼(gang)(gang)表(biao)面(mian)(mian)(mian)(mian)電(dian)(dian)鍍(du)(du)是將表(biao)面(mian)(mian)(mian)(mian)作為(wei)陰(yin)極以小電(dian)(dian)流活(huo)化(hua)(hua),利用(yong)陰(yin)極釋放的(de)原子態(tai)氫還原不(bu)銹(xiu)(xiu)鋼(gang)(gang)表(biao)面(mian)(mian)(mian)(mian)的(de)鈍化(hua)(hua)膜(mo)(或稱氧化(hua)(hua)膜(mo)),達到活(huo)化(hua)(hua)目的(de)。在(zai)此情(qing)況(kuang)下,為(wei)使(shi)漏鍍(du)(du)的(de)不(bu)銹(xiu)(xiu)鋼(gang)(gang)活(huo)化(hua)(hua),又要使(shi)鉻(ge)層(ceng)表(biao)面(mian)(mian)(mian)(mian)活(huo)化(hua)(hua),應(ying)選擇陰(yin)極活(huo)化(hua)(hua)為(wei)主(zhu),陽極腐(fu)蝕為(wei)輔(fu)的(de)辦法,即鍍(du)(du)件(jian)先作為(wei)陽極腐(fu)蝕2min,再陰(yin)極活(huo)化(hua)(hua)時間相當(dang)于15min,隨后陰(yin)極電(dian)(dian)流逐步(bu)(bu)上升,不(bu)銹(xiu)(xiu)鋼(gang)(gang)表(biao)面(mian)(mian)(mian)(mian)和(he)鉻(ge)層(ceng)表(biao)面(mian)(mian)(mian)(mian)逐步(bu)(bu)達到鉻(ge)的(de)析(xi)出電(dian)(dian)位,沉積(ji)了鉻(ge)層(ceng)。




3. 補(bu)鍍硬鉻工藝(yi)流(liu)程(cheng)


 化學(xue)除油(用(yong)去油劑在室溫(wen)下擦洗(xi))→水(shui)洗(xi)→酸洗(xi)[鹽酸10%(質量(liang)分數(shu))清洗(xi)]→水(shui)洗(xi)→酸洗(xi)漏鍍處(4+1氫氟(fu)酸)→水(shui)洗(xi)→人槽→預熱(re)→陽極(ji)腐蝕(DA15~20A/d㎡,時(shi)間(jian)(jian)2min)→陰(yin)極(ji)活(huo)化(DK 5A/d㎡2,階梯遞升(sheng)(sheng)電流(liu),每隔1~2min提升(sheng)(sheng)一次(ci)電流(liu),提升(sheng)(sheng)幅度1~4A/d㎡,約提升(sheng)(sheng)8次(ci),共(gong)10~15min升(sheng)(sheng)至(zhi)正(zheng)常電流(liu))→正(zheng)常鍍鉻(DK 15~40A/d㎡,時(shi)間(jian)(jian)鍍至(zhi)最小厚度超過所(suo)需厚度)→水(shui)洗(xi)→檢驗(yan)→除氫。


 經過上述工藝流程的補鍍(du)(du)鉻,原來漏鍍(du)(du)處經檢(jian)查(cha)也全部補鍍(du)(du)齊,無一處鉻層脫(tuo)落。