Research On Laser Cladding Strengthening Technology Of Circulating Pump Impeller Of Polysilicon Quench Tower

As a new green manufacturing technology,laser cladding technology can repair failed parts in a pollution-free environment,keep the failed parts in service,reduce environmental pollution and increase social and economic benefits.It is a technological innovation in modern industry.In this paper,the wear mechanism and failure modes of the impeller of the circulating pump are studied,and based on the conclusions drawn,the optimal process parameters and technical routes are formulated for the repair and protection of the impeller.The melt is prepared by technical means such as laser cladding and laser remelting.The cladding layer,through the research on the performance of the cladding layer,has verified the protection and strengthening effect of the cladding layer on the impeller.(1)The surface morphology of the failed old impeller was scanned by electron microscope,and the surface attachment was analyzed by EDS.It was concluded that the impeller was subjected to long-term high-speed movement of silicon particles on the surface,causing local wear failure and peeling,and the impeller surface was caused by fluid erosion and cavitation.The furrow is formed,and the electrochemical corrosion further expands the furrow.Because the impeller works in an acidic environment for a long time,the impeller is subjected to acid corrosion,which eventually causes the impeller to fail.(2)A repair and strengthening plan was developed for the impeller manufacturing material,service environment and failure mode.The design verification test obtained the influence of power on the surface morphology,which provided a reference for the formal test,and the orthogonal test was designed to obtain the best process parameters.,Using scanning electron microscope,X-ray energy spectrometer,X-ray diffractometer,Vickers hardness tester,abrasion tester,etc.to study the cladding layer,it is obtained that the current power is 1000 W,the scanning speed is 6 mm/s,and the powder feeding speed is 1.5 r/min.The effect of the cladding layer is the best at/min.The hardness of the cladding layer is 487.2 HV_0.2and the wear amount of the cladding layer is 46.6%of the matrix through the performance study of the cladding layer.(3)The remelted layer was prepared by laser remelting technology,and the remelted layer was studied.The test results showed that the surface morphology of the remelted layer was good and there were no obvious defects in the structure.The hardness of the remelted layer was 658.5 HV_0.2,which was much higher than Base material hardness,under the same wear test conditions,the base material wear loss weight is 0.0751 g,the cladding layer wear loss weight is 0.0350 g,the remelting layer wear loss is 0.0211 g,the remelting layer wear is 28.1%of the substrate,and the friction coefficient is both It is smaller than the base material,and the test proves that the prepared cladding layer meets the requirements of protection and strengthening performance of the impeller.The impeller surface repaired by color flaw detection has no obvious defects such as cracks.