| Different from the research and development of traditional new materials and new coatings.It explores the erosion mechanism and slurry erosion behavior of the type,dimension,and form of the groove surface microstructure in the liquid-solid two-phase flow through the rotary disc erosion test method and computational fluid dynamics method,with the help of mass loss measurement,micro-topography observation technology,roughness measurement technology and residual stress detection technology.The main section of the experiment was carried out on a self-made turntable erosion device.The sample material was commonly used corrosion-resistant 304 stainless steel（UNS 30400）.The solution was a slurry with a sand size of 70-150 mesh.The relative velocity between the sample and the solution was about 8 m/s.A comparative study of three types of groove surface microstructures（V-shape,Ushape,and ring-shape）against erosion shows that in the liquid-solid erosion conditions,the erosion resistance of the microstructures from strong to weak is V-shape,ring-shape,and Ushape groove structure.The ER（degree of erosion damage）of the V-shape groove structure is 69%of that of the U-shape groove and 93%of the ring-shape groove structure.The top surface of the groove and the inside of the groove are respectively subjected to different degrees of liquid-solid erosion.Among them,the incident flow surface of the V-shape groove and the U-shape groove,and the bottom surface of the ring-shape groove are most severely eroded by liquid and solid.The vortex in the groove is like a cylindrical roller bearing,which can reduce the sidewall resistance.In addition,the vortex not only has a scouring effect on the inside of the groove,but also has a certain degree of erosion on the top surface of the groove.In general,the V-shape groove has the best liquid-solid erosion performance.Based on the above research results,based on the V-shape groove,five groove depths（1 mm-V1,2 mm-V2,3 mm-V3,4 mm-V4,5 mm-V5）for material erosion were further studied the effect of the erosion performance.The results show that in the conditions of a concentration of 3%wt and a relative velocity of 8.29 m/s between the sample and the solution,the best erosion resistance performance occurs at the critical depth V3 of the surface microstructure.Part of this is due to the low velocity component of the flow direction and the upward velocity component perpendicular to the flow direction.This velocity distribution can inhibit the erosion of particles in the groove,and at the same time prevent sand particles from re-entering the groove for erosion.The symmetry of the V-shape groove structure also has a certain impaction on the erosion resistance of the microstructure.The results show that,compared with smooth surfaces,not all asymmetric surface designs can alleviate liquid-solid erosion.The influence of five asymmetric microstructures（R1-R5）on erosion performance was studied.The erosion resistance of the left-tilted microstructures（R4,R5）was significantly better than that of the right-tilted microstructures（R1,R2）.Erosion of the IS（incident flow surface）in the groove dominates’ the erosion process.Most of the particles impact the surface of 14（the incident flow surface of R4）at a large angle,resulting in a low material removal rate,and the thickest low-velocity layer above the groove,resulting in a large amount of energy consumed for particle impact.These two factors are the main reasons why R4 has the best erosion resistance.It can also be found that both R4 and symmetrical R3 have an upward velocity component in the Y direction,which can change the particle trajectory and reduce the erosion of TS（top surface）.This article mainly describes the liquid-solid erosion mechanism of surface microstructures,provides theoretical guidance for the design and optimization of microstructures,and explores new possibilities and ideas for anti-erosion methods. |
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