Study On High Temperature Oxidation And Corrosion Characteristics Of A Nickel Based Alloy

In order to meet the requirements of the harsh environment for the use of a gun tube,rocket engine,and other weapons,such as a rocket engine,This paper develops a kind of nickel base alloy which is suitable for the environment.Experiments on high temperature oxidation and corrosion of the nickel base alloy under different working conditions are carried out,Thermal gravimetric analysis,X ray diffraction analysis?XRD?,Scanning electron microscopy?SEM/EDX?and other means,Analysis of high temperature oxidation mechanism and thermal corrosion mechanism of nickel based alloy,Provide theoretical basis for the application and development of the hot end components of the alloy used in the harsh conditions of the ocean.The oxidation kinetics curves of 300 h at 900 and 1000 respectively follow the oxidation kinetics of the alloy at the and respectively,Then the weight loss phenomenon occurs alternately,The whole process tends to be flat and wavy.The process is more obvious with the increase of oxidation temperature.And Al₂O₃ oxides were generated at900 and 1000,respectively,and NiO,300 h,And NiCr₂O₄ spinel structure oxide,NiCo₂O₄ oxide under 900 conditions at 1000,And the substance was cured with Ta and Cr elements,Generate CoTa₂O₆ and CoCr₂O₄ compounds.In the condition of900 and 1000,nickel base alloy has been significantly oxidized and internal nitriding is all over,The inner oxide and inner nitride are in a hierarchical distribution,Distinguish clearly.Inner oxide appears in the interface between the alloy and the oxide film,Al element oxides are mainly needle bar,The inner nitride is AlN,which is below the oxide.Mixed sulfate?wt%?corrosion of 65 h and 30 h.at 900 and 950,respectively,was and 75%Na₂SO₄+25%K₂SO₄,respectively.Corrosion kinetics curves in the early and late stages of a marked deviation,The corrosion rate of the alloy in the late stage of corrosion is slow,The corrosion mechanism of nickel based alloys in this condition has changed.The corrosion of the nickel base alloy at 900 and 950 is similar to the basic,Mainly Al₂O₃ and Ni oxides and sulfides.Throughout the experiment,The oxidation and corrosion of nickel based alloys were carried out simultaneously.The interior of the alloy also has an inner oxide Al₂O₃ generation,At the same time,the interior of the alloy has been formed,With the increase of the temperature of the experiment,it is obviousthat the internal sulfide is rich in Cr.