Abstract: A method of treating a part made of an aluminum alloy containing copper at a content in the range 0.1% to 10% by weight includes providing the part; and performing electrochemical pretreatment of the part in a first electrolyte bath containing sulfuric acid and a first oxidizer compound, a first potential difference being established between a first cathode and a first anode dipped in the first bath, the part being the first anode, the concentration of the first oxidizer compound being such that the corrosion potential of the aluminum alloy is greater than +100 mV relative to a hydrogen normal electrode. After the pretreatment, the method includes anodizing the part in a second electrolyte bath containing sulfuric acid and a second oxidizer compound, a second potential difference ?V2 being established between a second cathode and a second anode dipped in the second bath, the part being the second anode.

Abstract: The invention provides a method of operating a thermal installation comprising a combustion chamber fed with a fuel contaminated with vanadium, with sulphur and possibly with sodium. In particular, the combustion chamber is also fed with boron and with magnesium, in quantities such that the sodium molar ratio s=Na2SO4/V2O5, the magnesium molar ratio m=MgO/V2O5 and the boron molar ratio b=B2O3/V2O5 satisfy the equation m?3+2b?s, so that the combustion products comprise magnesium orthovanadate, mixed magnesium boron oxide and possibly sodium borate. The invention also provides for the use of such a method to inhibit corrosion of the thermal installation by vanadium oxide, possibly in the presence of sodium.

Abstract: The invention relates to a method for the carboxylation conversion of a metal surface under oxidizing conditions in relation to the metal, consisting in bringing the metal into contact with a hydro-organic or aqueous bath containing a mixture of organic acids. The invention is characterized in that; the organic acids comprise saturated linear carboxylic acids having between 10 and 18 carbon atoms; the mixture comprises a binary or ternary mixture of such acids; the respective proportions of said acids are such that (i) for a binary mixture x±5%?y±5%, wherein x and y represent the respective proportions, in molar percentages, of the two acids in a mixture with the composition of the eutectic and (ii) for a ternary mixture x±3%?y±3%?z±3%, wherein x, y and z represent the respective proportions, in molar percentages, of the three acids in a mixture with the composition of the eutectic; and the concentration of the mixture in the bath is greater than or equal to 20 g/l.

Abstract: The invention provides a method of operating a thermal installation comprising a combustion chamber fed with a fuel contaminated with vanadium, with sulphur and possibly with sodium. In particular, the combustion chamber is also fed with boron and with magnesium, in quantities such that the sodium molar ratio s=Na2SO4/V2O5, the magnesium molar ratio m=MgO/V2O5 and the boron molar ratio b=B2O3/V2O5 satisfy the equation m?3+2b?s, so that the combustion products comprise magnesium orthovanadate, mixed magnesium boron oxide and possibly sodium borate. The invention also provides for the use of such a method to inhibit corrosion of the thermal installation by vanadium oxide, possibly in the presence of sodium.

Abstract: The invention relates to a method for the carboxylation conversion of a metal surface under oxidising conditions in relation to the metal, consisting in bringing the metal into contact with a hydro-organic or aqueous bath containing a mixture of organic acids. The invention is characterised in that; the organic acids comprise saturated linear carboxylic acids having between 10 and 18 carbon atoms; the mixture comprises a binary or ternary mixture of such acids; the respective proportions of said acids are such that (i) for a binary mixture x±5%?y±5%, wherein x and y represent the respective proportions, in molar percentages, of the two acids in a mixture with the composition of the eutectic and (ii) for a ternary mixture x±3%?y±3%?z±3%, wherein x, y and z represent the respective proportions, in molar percentages, of the three acids in a mixture with the composition of the eutectic; and the concentration of the mixture in the bath is greater than or equal to 20 g/l.

Abstract: The invention concerns inhibition of vanadium corrosion of thermal equipment materials burning vanadium-contaminated liquid fuels using nickel compounds. The invention is applicable in particular to liquid fuel combustion in gas turbines.