| Stainless steel has a wide range of applications in chemical,pharmaceutical,food,household and building decoration industries because of its excellent corrosion resistance,moldability,wide temperature range of strength and toughness,economy and applicability.Polishing treatment is needed for products after molding in order to gain good performance and smooth appearance,especially in pharmaceutical,food and chemical industries.There are mainly two methods to polish the inner surface of stainless steel products at present,including pickling and electrochemical machining method.Besides,some scholars researched mechanical grinding equipment for inner surface polishing of stainless steel tubes.Pickling and electrochemical machining are costly.The effluent of them is also pollutiveand hard to dispose.Plentiful metal powder can be produced through mechanical polishing process.Moreover,only the workpiece with simple structure can be processed and it is hard to handle the workpiece with complex morphology.Therefore,it is meaningful to search an efficient and environmental friendly polishing method to process stainless steel inner surface.Based on the problem of inner surface polishing of stainless steel products,the related exploration and research about plasma electrolyte polishing technology of stainless steel inner surface have been researched in this paper.Electrolyte plasma processing technology was introduced into inner surface polishing of stainless steel products instead of the traditional polishing method,in order to obtain a good processing result.It is aimed to find out the best inner surface polishing process for some stainless steel products,providing a newinner surface polishing method and laying a foundationfor follow-up studyas well.Electrolyte plasma processing technology uses clean electricity and low concentration of salt solution which can polishcomplex topography of metal products,greatly reducing the equipment cost,simplifying operation and polishing process.The experiment proved that the electrolyte plasma processing technology can polish the inner surface of stainless steel products,improving the quality of surface.The conditions of the electrolyte plasma process have been given and analyzed in this paper based on The mechanism of electrolyte plasma deburring,polishing process.The center electrode method is put forward,and experimental process is madebased on 304 stainless steel pipes for finding out the voltage parameters and polishing method of the stainless steel pipe inner surface.A platform for inner surface polishing experimentsis set up,and series of tests have been carried outon this basis.The influence of using various process parameters in the inner surface roughness is found,before obtaining the basic rule of the plasma surface polishing by the electrolyte.Further orthogonal experiments are focused on the electrolyte flow rate,electrolyte temperature,electrolyte concentration and timeas influence factors and the result has been analyzed,obtaining the optimum processing parameters.Optimal parameters have been used toprocess the stainless steel pipe withthe diameter of 25 millimeters,the length of 50 millimeters and the thickness of 0.6millimeters and the slice which is 10 millimeters under the port in of Stainless steel pipe has been tested by OLS3000 focusing microscope.The topography and roughness of the inner surface before process and after process are compared and a solution is found that the surface roughness changed from the initial 0.6113?m to 0.054?m.Subsequently,stainless steel inner blind hole is polished,obtaining excellent surface roughness.Further analysis about characteristics of stainless steel vacuum cup and polishing requirements are discussed so as to design the special fixture on the vacuum cup polishing and improve the roughness of the inner surface of the thermos cup. |
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