V To K417G Alloy Of High Temperature Oxidation And Hot Corrosion Resistance

K417G nickel base alloy with high strength,excellent mechanical properties,high temperature performance and other characteristics, is mainly used in the manufacture of aviation, navigation and other machine for gas turbine engine components, and it is an important material of manufacturing. The high temperature alloy is often working under high temperature environment, and it is long-term in combustion and oceanic and atmospheric, its performance in addition to the requirements with good mechanical properties at high temperatures, also needs to consider the high temperature hot corrosion resistance of alloy, the corrosion resistance of the alloy is an important parameter, it directly affects its application area and service life. The modification of the alloy by adding V can improve the high temperature mechanical performance of alloy appropriately, but V of the alloy at high temperature hot corrosion and oxidation resistance of impact study also play an important role in alloy applications.Using X-ray diffraction(XRD), scanning electron microscope(SME) and high temperature online methods of electrochemical measurement, and studying the influence of V of K417 G alloy in 900 ℃/100 h surface with polish salt(25% NaCl + 75% Na2SO4) heat resistant corrosion performance, and high temperature performance. The results show that the hot corrosion rates with the increase of the content of V alloy. If the content of V is lower than0.6%, the corrosion rate increases only a little, the corrosion rate of 0.06% V alloy is four times as large as 0.016% V alloy; When the V content is more than 0.6%, the alloy of the heat corrosion rate increases rapidly, when the V content increases to 1.19%, compared with0.016% V alloy, alloy hot corrosion rate increases more than 100 times. Alloy at 900 ℃ under the corrosion layer is divided into corrosion surface and subsurface, of which the surface enrichment has the main elements of Al, Ti, Cr, O, Al2O3, NiO and chemical compounds such as TiO, the subsurface has a lot of S, Mo, Ni elements, forming the NiS, MoS and NiCrS compounds.Corrosion products is mainly the oxide and sulfide. Oxide is Al, Cr, Co, Ni and Ti oxide,the sulfide is mainly NiS, MoS and NiCrS, with the increase of content of V, S diffusion, and the oxide layer of Al in alloy surface beomes thinner, which makes the alloy corrosion layer density decreased, when the V is low, sulfide is formed outer surface, and when the V is high,sulfide layer is close to the substrate, which the V4 alloy appear fall off.V of K417 G alloy oxidation performance under 900 ℃ the research results show that the alloy under 900℃ isothermal oxidation kinetic curves follow a parabolic law, with the increase of content of V, oxidation rate increases gradually, V content lower than 0.6%, the oxidation rate increase amplitude is small, the V content exceeds 0.6%, oxidation rate increased rapidly,1.19% V content in the alloy oxidation rate is 100 times of low V(0.016%).Alloy oxide layer is divided into inner and surface, surface enrichment of Al, Ti, Cr, Co, Ni, V, the formation of Al2O3, TiO2, and a small amount of Cr2O3, Ni3V2O8, CoCr2O4, NiTiO3 spinel phase group compounds;Inner enrichment of Ni, Al, Ti, Cr, Mn, Co, elements, the formation of NiO, Al2O3,TiO2, part of Cr2O3 compounds and MnCo2O4 compound spinel phase composition, along with the increase of the content of V element Al, Cr, Ti, gradually spread to the surface, O element diffusion to the matrix, and when the V content increased to maximum, the surface oxidation product appear fall off phenomenon.Sample alloy to add just the right amount of metal V(0.016%), has a positive meaning for the high temperature oxidation resistance.High temperature polarization curve, according to the results, compared with 1.19% V alloy low V alloy(0.016%) of the corrosion potential to move forward the 0.4 V, low V alloy has good heat resistant corrosion, high V alloy heat corrosion performance degradation.By means of chemical immersion method V of K417 G alloy in 6% FeCl3 + 0.05 mol/L HCl solution under the condition at 50 ℃ for 24 h after the intergranular corrosion properties of the influence of, with the increase of the content of V, the corrosion rate increase. corrosion resistance is the worst.Studied the temperature effect on the performance of different content of V alloy electrochemistry, the results showed that 2.5% NaCl + 7.5% Na2SO4 solution in different temperature, with the temperature increased, the corrosion resistance decrease, and at the same temperature, V1 alloy have better corrosion resistance.