High Temperature Wear Performance Of Heat Resistant Steel S51740 Based On ANSYS LS-DYNA

Heat-resistant steel S51740 is widely used in gas turbine compressor rotor blades and other hot-end components due to its excellent oxidation resistance and thermal strength.The main reasons for its failure are high temperature oxidation corrosion,friction and wear between blades and casing,and foreign matter erosion wear,etc.In this study,high temperature oxidation was combined with two factors,high temperature friction wear and high temperature erosion wear,and the wear characteristics of materials were studied by combining finite element numerical simulation.Research indicates:With the increase of oxidation temperature and time,the size and number of oxides continue to increase,mainly spinel-like Cu Cr₂O₄ and Mn Cr₂O₄ particles,and the formation mechanism is mainly through the outward migration of metal elements and the reaction with oxygen;the oxidation weight gain curve conforms to the parabolic growth law;Continuous cyclic oxidation is equivalent to multiple heat treatment of the material,so that the microstructure and physical properties of the material have changed compared with the heat treatment state.After 100 hours of cyclic oxidation,the thickness of the oxide layer on the surface of the material at 400℃,600℃and 800℃is 1 um,2 um and 5 um,respectively,and the thickness of the oxidation affected zone is 10 um,20 um and 50 um,respectively.The matrix dropped by 12%,15%and 20%.At 400℃and 600℃,the amount of friction and wear and erosion wear are small,and the mass loss increases significantly at 800℃.The mechanical properties of the material decrease greatly at 800℃,and the wear resistance is poor,so it is not suitable for long-term service at this temperature.It has good thermal strength and wear resistance within 600℃,and effective control of the use temperature can reduce wear.In the process of friction and wear,at 400℃,friction oxides are formed on the grinding surface,which has a certain lubricating effect on the wear and slows down the material wear.The grinding surface has obvious furrows,and the wear forms are mainly oxidative wear and abrasive wear.At 600℃,the coverage of friction oxides increases,and there are a few furrows on the grinding surface.The wear forms are dominated by oxidation wear,and there are abrasive wear and adhesive wear at the same time.At 800℃,the friction oxides evenly cover the surface of the substrate,and there are multiple layers of friction oxides,which are loosely combined with the substrate and lose their protective effect on the substrate.The wear forms are mainly oxidative wear and adhesive wear.In the process of erosion wear,the main failure mode of the material is that the cutting action of the erosion particles on the material causes the material to undergo plastic deformation beyond the shear limit and then fall off,and the plastic deformation gradually intensifies with the increase of temperature.Through numerical simulation,it is found that at the junction of the oxidation-affected zone and the substrate,the stress and strain distribution curves of the target have inflection points,and the oxidation-affected zone will have a larger plastic strain than the substrate,which will accelerate the failure of the material during the wear process;In the process of friction and erosion,the rotating particles or erosion particles will convert most of the kinetic energy into the internal energy of the target material,which will increase the temperature of some units of the target material,thereby reducing the mechanical properties of the local material and accelerating the wear of the material.Moreover,the lower the ambient temperature,the more obvious the temperature rise,and the more significant the impact on the wear resistance of the material.In this study,the high temperature wear characteristics of the material were investigated by a combination of experiments and numerical simulations.It is of great significance to prevent material wear and failure and further prolong the service life of materials.