The Synergism Between Corrosion And Wear Of Nickel-based Alloy K4169 In Artificial Seawater

Corrosion and wear failure of resistant materials of nickel-based alloys is one of the problems to be solved urgently in ocean development.The synergism between corrosion and wear,environment induced embrittlement as well as surface film formation and failure constitute the main research contents in the field.In this thesis,corrosion and wear behavior of K4169 alloy in artificial seawater were studied by Corrosion Wear Instrument.And how electrochemical parameters(potential,solution temperature)and tribological parameters(normal load)affect the total loss rate,wear loss rate,corrosion loss rate and synergistic component rate of material were primarily investigated.Through the establishment of tribo-corrosion map based on parameters about normal load vs potential and solution temperature vs potential,which included material wastage map,mechanism map,synergistic map,environmental embrittlement and formation and failure of surface film were investigated under cathodic protection.The main results and conclusions are as follows:1.K4169 alloy has good corrosion resistance performance in artificial seawater owing to the formation of stable corrosion resistance passivation film on its surface.With the increase of solution temperature,the corrosion resistance of K4169 alloy in artificial seawater decreased,and it was prone to crevice corrosion at high temperature.K4169 alloy has better corrosion resistance than K418 alloy and two stainless steel(310S and 304).2.The potentiodynamic polarization curves show that the mechanical removal of the surface passivation film leads to the corrosion rate of K4169 alloy higher 102?103 times than that of the static.3.Corrosion wear mechanism diagram based on parameters about normal load vs potential shows that the wear loss rate Wc constitutes 87.1%?96.8%of total loss T;the synergistic map shows the antagonism effects,synergistic effects and additive effects all exist,but synergistic effects dominate.4.The results of tribo-corrosion behavior of K4169 alloy in artificial seawater which is based on the solution temperature and potential show that the effect of solution temperature on the tribo-corrosion behavior of the alloy is more complicated.5.Potential(-1 V and-0.6 V)and solution temperature caused some pHysical and chemical changes under the cathodic protection such as electrochemical reaction on the alloy surface(hydrogen evolution and oxygenation reaction)and solution chemistry reaction(Mg(OH)2 deposition and the precipitation of Na2SO4),which could affect determination of pure mechanical wear loss quantity.XPS and TOF-SIMS data confirmed the composition of surface film and the distribution of H+.