Investigation On The Regulation Of Inter-facial Properties In The Laser Cladding Repair Zone Of Metro Wheels With Local Damage

For subway wheels,wheel-rail contact behavior is complicated during service,and the interface of laser cladding repair area with local damage is more likely to be damaged,which directly affects the using effect after damage repair.Therefore,it is necessary to systematically analyze the influencing factors of interface performance of laser cladding repair for local wheel damage,and reveal its performance and control methods,so as to provide a path for optimization of laser cladding process for local wheel damage of rail vehicles and ensure the quality of damage repair.The objective of the study is to clarify the failure form and failure mechanism of the interface in the laser clad repair zone of metro wheels with local damage by laser cladding repair of metro wheel specimens under local rim damage.By constructing a numerical simulation model of the laser cladding repair process of localized damage of subway wheels under the intervention of external energy field and synchronous thermal field,the study method analyzes the relationship between the external energy field parameters and the interfacial structure and properties of the laser cladding repair area;and analyzes the microscopic morphology and mechanical property test results of the samples to optimize and improve the method of regulating the interfacial properties of laser cladding repair of localized damage of subway wheels with the intervention of external energy field and to perform process curing.The research content takes the repair of localized damage of subway wheels as the research object,takes the regulation of the interface performance of the laser cladding repair area as the target,focuses on the evolution of the interface performance and failure mechanism of the laser cladding repair area of localized damage of subway wheels,explores the influence of the external energy field regulation parameters on the interface structure,residual stress distribution,hardness and bond strength of the repair area through numerical simulation analysis,and reveals the relationship between the external energy field regulation parameters The optimal matching relationship between the external energy field regulation parameters and the interfacial properties of the laser clad repair zone is revealed.The evolution of the tissue structure,residual stress distribution,hardness,and bond strength of the interface area of the laser clad repair coating with localized damage is analyzed.The optimized external energy field regulation parameters are optimized based on the experimental results;the optimized external energy field is applied to the laser cladding repair process of real subway wheel surface with localized damage to further optimize the interface performance regulation parameters and solidify the interface performance regulation of laser cladding repair of subway wheels with localized damage process.The specific results of the study are that the temperature of the synchronous thermal field will superimpose the temperature of the overall temperature field,but the temperature of the highest value will not superimpose too high,and the difference between the highest value temperature is smaller under the 3 types of temperature parameters,but the lowest temperature has a large increase,which helps to reduce the span value of the temperature gradient and ensure the leveling of the temperature gradient at the interface,and the temperature at the interface increases with time change graph temperature,but the lowest temperature and the highest temperature The difference is smaller,and the simulation effect is better for the synchronous thermal field of 200 °C.With the increase of the temperature of the synchronous thermal field,the value of the equivalent effect force decreases,and at the same time,the stress of the interface path in the three directions of the normal stress is lower than the case without the addition of the synchronous thermal field.With the increase of the synchronous hot field temperature,the tissue distribution at the melt layer and interface is uniform and shows good metallurgical bonding.The synchrothermal field assistance causes the hardness to increase with increasing temperature,while the impact toughness and tensile properties decrease.In order to match the reason of the wheel in daily service,the synchrothermal field is selected at 100 °C for Fe based materials with better performance and200 °C for stainless steel materials with better performance.