Effects of electroplated coatings on corrosion behavior of Ti-1023/30CrMnSiA galvanic couple

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled 30CrMnSiA steel was investigated in 3.5% NaCl solution. Particular attention was given to the effect of three different electroplated coatings on corrosion behavior of the galvanic couple. Galvanic corrosion test was conducted on Ti-1023 titanium alloy which coupled Ni-electroplated 30CrMnSiA, Zn-electroplated 30CrMnSiA, Cd-electroplated 30CrMnSiA and bare 30CrMnSiA, respectively. Corrosion properties including open circuit potential (E _oc ), galvanic corrosion potential (E _g ), and galvanic corrosion current (I _g ) were monitored. Corrosion morphology was observed by optical microscope (OM) and corrosion mechanism was analyzed and discussed. The results show that the three electroplated coatings improve the corrosion resistance of the anode in different magnitudes. Ni-electroplated 30CrMnSiA and Cd-electroplated 30CrMnSiA coatings are found to be least susceptible to galvanic corrosion when coupled Ti-1023 titanium alloy. Zn-electroplated 30CrMnSiA is moderately susceptible to galvanic corrosion. But the bare 30CrMnSiA is highly susceptible to galvanic corrosion in corrosive environment.