1. 補鍍硬鉻的適應性


a. 由于電(dian)網停電(dian),鍍鉻(ge)中途斷電(dian),來(lai)電(dian)后需要繼續補鍍鉻(ge)以(yi)達到規(gui)定厚度者。


b. 由于工作上的失誤,不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. 鍍完硬鉻后(hou)鉻層(ceng)厚度未達到(dao)規定(ding)尺寸(cun),或在磨(mo)光硬鉻層(ceng)后(hou)產品尺寸(cun)未達規定(ding)要(yao)求者。


 以上諸種情況,可(ke)以不采用(yong)退除鉻層重鍍(du)鉻,而(er)可(ke)實施在(zai)表面上補鍍(du)硬鉻。



2. 工藝分析


  鉻(ge)(ge)(ge)(ge)(ge)上補鍍(du)(du)(du)鉻(ge)(ge)(ge)(ge)(ge)和(he)不(bu)(bu)(bu)銹(xiu)鋼鍍(du)(du)(du)鉻(ge)(ge)(ge)(ge)(ge)的(de)表面(mian)(mian)活(huo)化(hua)(hua)(hua)處理不(bu)(bu)(bu)盡相同(tong),鉻(ge)(ge)(ge)(ge)(ge)上鍍(du)(du)(du)鉻(ge)(ge)(ge)(ge)(ge)是要將鍍(du)(du)(du)鉻(ge)(ge)(ge)(ge)(ge)表面(mian)(mian)作(zuo)為(wei)陽(yang)(yang)極(ji)(ji)(ji)進(jin)(jin)行腐(fu)(fu)蝕(shi)一(yi)定時(shi)間,以(yi)形成微觀粗糙的(de)活(huo)化(hua)(hua)(hua)表面(mian)(mian),再將鍍(du)(du)(du)件轉換成陰(yin)極(ji)(ji)(ji),再階梯(ti)遞(di)升(sheng)電(dian)(dian)(dian)流到(dao)工藝規范的(de)電(dian)(dian)(dian)流進(jin)(jin)行鍍(du)(du)(du)鉻(ge)(ge)(ge)(ge)(ge)。不(bu)(bu)(bu)銹(xiu)鋼表面(mian)(mian)電(dian)(dian)(dian)鍍(du)(du)(du)是將表面(mian)(mian)作(zuo)為(wei)陰(yin)極(ji)(ji)(ji)以(yi)小電(dian)(dian)(dian)流活(huo)化(hua)(hua)(hua),利用陰(yin)極(ji)(ji)(ji)釋放的(de)原子態氫還(huan)原不(bu)(bu)(bu)銹(xiu)鋼表面(mian)(mian)的(de)鈍化(hua)(hua)(hua)膜(mo)(或(huo)稱(cheng)氧化(hua)(hua)(hua)膜(mo)),達(da)到(dao)活(huo)化(hua)(hua)(hua)目的(de)。在此(ci)情況下,為(wei)使(shi)漏鍍(du)(du)(du)的(de)不(bu)(bu)(bu)銹(xiu)鋼活(huo)化(hua)(hua)(hua),又要使(shi)鉻(ge)(ge)(ge)(ge)(ge)層(ceng)表面(mian)(mian)活(huo)化(hua)(hua)(hua),應(ying)選擇陰(yin)極(ji)(ji)(ji)活(huo)化(hua)(hua)(hua)為(wei)主(zhu),陽(yang)(yang)極(ji)(ji)(ji)腐(fu)(fu)蝕(shi)為(wei)輔的(de)辦(ban)法(fa),即鍍(du)(du)(du)件先作(zuo)為(wei)陽(yang)(yang)極(ji)(ji)(ji)腐(fu)(fu)蝕(shi)2min,再陰(yin)極(ji)(ji)(ji)活(huo)化(hua)(hua)(hua)時(shi)間相當于(yu)15min,隨后(hou)陰(yin)極(ji)(ji)(ji)電(dian)(dian)(dian)流逐步(bu)(bu)上升(sheng),不(bu)(bu)(bu)銹(xiu)鋼表面(mian)(mian)和(he)鉻(ge)(ge)(ge)(ge)(ge)層(ceng)表面(mian)(mian)逐步(bu)(bu)達(da)到(dao)鉻(ge)(ge)(ge)(ge)(ge)的(de)析出電(dian)(dian)(dian)位,沉積(ji)了鉻(ge)(ge)(ge)(ge)(ge)層(ceng)。




3. 補(bu)鍍硬鉻工藝流程(cheng)


 化(hua)(hua)學除油(用去油劑在室溫下(xia)擦洗(xi)(xi)(xi))→水洗(xi)(xi)(xi)→酸洗(xi)(xi)(xi)[鹽酸10%(質量分(fen)數)清洗(xi)(xi)(xi)]→水洗(xi)(xi)(xi)→酸洗(xi)(xi)(xi)漏鍍(du)處(4+1氫氟酸)→水洗(xi)(xi)(xi)→人(ren)槽(cao)→預熱→陽極腐(fu)蝕(shi)(DA15~20A/d㎡,時間2min)→陰極活化(hua)(hua)(DK 5A/d㎡2,階梯遞升電(dian)流(liu)(liu),每(mei)隔1~2min提升一次(ci)電(dian)流(liu)(liu),提升幅(fu)度(du)(du)1~4A/d㎡,約提升8次(ci),共10~15min升至正(zheng)常電(dian)流(liu)(liu))→正(zheng)常鍍(du)鉻(ge)(DK 15~40A/d㎡,時間鍍(du)至最小厚度(du)(du)超過所需(xu)厚度(du)(du))→水洗(xi)(xi)(xi)→檢驗→除氫。


 經過上述工(gong)藝流程的補(bu)鍍鉻,原來漏鍍處經檢查也全部補(bu)鍍齊,無一處鉻層脫落(luo)。