V2O5 ACCELERATED HOT CORROSION OF NICKEL IN ALKALI SULFATES MELT

Effect of addition of V2O5 on hot corrosion of nickel in alkali (Li, N a, K)(2)SO4 melts has been studied at 550 degrees C by electrochemical polarization method. Corrosion potential (E-corr) observation under o pen circuit potential (OCP) condition attributes a shift of E-corr in positive potential direction with the increase of V2O5 concentration i n the melt. Corrosion rate (I-corr) measurement indicates an order of magnitude higher oxidation rate in presence of even 1% V2O5 while thre e orders of magnitude higher oxidation rate is noted after addition of 5 % V2O5 in the melt. XRD analysis of the scale identifies the presen ce of NiS, NiS2 Ni(VO3)(2) as major constituents of the scale alongwit h other minor constituents.