APPLICATION OF POLYPYRROLE TO GALVANIC ANODICPROTECTION OF STAINLESS STEEL IN H2SO4 SOLUTIONS

摘要

In order to investigate the galvanic anodic protection (GAP) of stainless steels by dopedrnpolypyrrole (Ppy), separate doped Ppy powder-pressed electrodes with different surface areas (the arearnratio of the Ppy electrode to stainless steel is among 1:1 and 1:2) have been prepared. Then thernelectrochemical properties of the Ppy electrode were studied by open circuit potentials andrnpotentiostat polarization. Then the Ppy powder-pressed electrodes were coupled with ferrous metal inrn1M and 5M H2SO4 solutions to construct a galvanic cell, in which Ppy is cathode while the steel isrnanode. Remarkable shift of open potential to the positive direction and sharp decrease of corrosion raternhave been observed during the coupling experiments, which implies the stainless steel transfers to thernpassive state. The results indicate Ppy electrode with sufficient area can provide corrosion protection tornstainless steel 410 in H2SO4 solutions, which is called Galvanic Anodic Protection.