New Type Of Te-Ni-Cr Alloy Of The High-temperature Oxidation Resistance

Many parts of the high-pressure steam boilers, steam turbine, gas turbines, diesel engines, aircraft engines and chemical refining equipment long-term service in high temperature conditions, so temperature is a predominant influence on the mechanical properties of materials. Usually because temperature increases and material oxidation, to change the material composition of the matrix, workpiece plastic deformation, and even rupture occurred in the service process, affected normal industrial production.Nickel-based alloy steel used in jet engines and gas turbine blades, requires a high temperature oxidation resistance and corrosion resistance. Nickel-based superalloy is the most complex, the most widely used in high temperature parts, and is concerned mostly by many alloy workers in all super alloys. At present, over 50% quality parts of advanced aerospace engine were composited by such alloys. In civilian areas have wider application.Tellurium is one of the scattered elements (Ga, In, TI, Ge, Se, Te, Re), and is the only element of high electronegativity and hard electron donor. Its physical and chemical properties were similar to sulfur and selenium. But compared to sulfur and selenium, it already had a significant metal nature. In recent years, with the rapid development of science and technology, scattered metal tellurium were concerned widespreadly in the metallurgical industry, electronic industry, chemical industry and other aspects, and achieved remarkable results.Because the antioxidant stability for nickel-chromium alloy was poor, tellurium elements were added to the nickel-chromium alloy in the study. By changing the micro-mechanism to achieve the purpose of strengthening, high temperature oxidation resistance was significantly improved. The Ni-base superalloy had wider applications. Meet the special requirements of materials on some high-tech fields.The Ni-Cr aolly was prepared by using P/M process and make the constant temperature oxidization experiment in 200±5℃,400±5℃,600±5℃,800±5℃. The alloys with different Te content were studied by means of the oxidation kinetic curves analyses,observing the oxide phase fracture surface and XRD. The results showed that: the inoxidizability of the aolly with Te was enhenced. Meanwhile, Cr₂TeO₄ and Fe₃TeO had formed in the alloy and the stickiness of the alloy had enhenced.and the volatilizition of Cr₂O₃ had been restrained, so, the compactness of the Cr₂O₃ oxidation layer had been improved. 1. Before oxidation ,because of the addition of Te, the aolly formed new complex phases.2. The oxidation kinetic curves showed the disciplinarian change after making the constant temperature oxidization experiment.3.Te had reduced the oxidation rate of Ni-Cr alloy, restrained growing of the oxide, reduced the microstructure flaw ,refining and blance the tissue of the aollys.4.The Ni-Cr aolly with Te addition had been improved in micromechanism so that the attachment of the oxide had been enhenced and reduced the drop of oxide skin.5. the friction experiment and corrosion experiment showed that the microstructure of the aolly had been changed , the abrasion resistant and corrosion resisting had been enhenced.6. In the oxidation experiment, according the differences of Te content, the oxidation degrees were significant different. The best fill in the amount of Te was evidenced in the experiment. Its comprehensive performance achieve the optimal when the Te content was 1.0%.