Galvanic Corrosion Behavior of Hastelloy C-276 Alloy and 16MnR Steel in Hydrochloric Acid

The galvanic corrosion behavior of Hastelloy C-276 alloy and 16MnR steel in 10%HCl solution was studied.The corrosion rates and steady state polarization curves of two metal materials were measured,and the effects of conjunction time,area ratio of cathode to anode,temperature and flow rate of corrosive fluid on anodic current density were investigated.It was found that the corrosion of Hastelloy C-276 alloy was retarded when it was coupled with 16MnR steel,but the corrosion rate of 16MnR steel anode rose significantly.The gap between the corrosion potentials of the two types of metal materials was over 200 mV,and the galvanic potential was close to the corrosion potential of 16MnR steel.The current of the galvanic couple continuously decreased with extending coupling time and tended to stabilize after 24 h of coupling.Besides,the anodic current density rose with increasing area ratio of cathode to anode and temperature as well,but did not vary linearly and tended to vary slowly at some point.Moreover,the anodic current density in flowing organic corrosive fluid was higher than that in stationary corrosive fluid.