Simulation Study On The Flow Field And Thermal Field Of Plasma Spray Welding Pool Under Excitation Magnetic Field

Plasma spray welding technology is a kind of typical remanufacturing field surface repair technology,with its energy concentration,and the advantages of high efficiency,easy to realize automation machinery in our country,power,defense and transportation industries such as the key component surface repair for a wide range of applications.In practical application,however,plasma spray welding technology is still in the process of process quality instability is easy to cause defects such as porosity,not fusion and oxide of the inclusion,coarse grains affect the mechanical properties of cladding layer prone to microscopic damage such as micro cracks,stress concentration,these problems restrict the development of plasma spray welding technology.Practice shows that conventional improvement methods to improve the quality of plasma spray welding effect is limited,but with the development of electromagnetic technology,magnetic field assisted processing is a more common way to improve quality of metal forming,magnetic field assisted welding become an important research direction.Molten pool as the most complex plasma spray welding process,the key part of the process parameters,magnetic field and magnetic field under the influence of process parameters on the molten pool,to promote the development of the technology in surface engineering has important research significance and application value.(1)In this paper,the influence of different spray welding technology on the plasma spray welding pool is investigated.Based on fluid mechanics,the basic theory of fluid dynamics and heat transfer fluid,comprehensive consideration in the process of spray welding molten pool in the form of convective heat transfer and thermal radiation,heat conduction and gravity,electromagnetic force,thermal buoyancy,surface tension and solid liquid phase change and phase change latent heat,the influence of such factors as plasma spray welding molten pool of the two-dimensional model is established,and on the basis of the model to explore the different current intensity and spray welding velocity of molten pool temperature field and the influence of flow field(2)Second in the plasma spray welding molten pool on the basis of two-dimensional model added magnetic field,considering the magnetic field on plasma heat source,the influence of forces on the molten pool etc,the building under the magnetic plasma spray welding molten pool two-dimensional model,and on the basis of the model to explore the different current under different magnetic field intensity and magnetic field intensity,the different spray welding velocity of molten pool temperature field and flow field.(3)Finally according to the simulation model set up under the same working conditions of plasma spray welding verification experiment,from the macroscopic Angle to observe different spray welding process parameters,different magnetic field intensity and magnetic field under different spray welding process parameters on the cladding layer width,thickness and the influence of penetration,and combining the micro Angle under the metallographic experiment to observe the changes of the microstructure of cladding layer,the results of simulation validate.