Application Research Of Surface Nanometer Thermal Spray On Pre-protect Of Vane Of Blast Top Gas Recovery Turbine Unit

With the increasing demand of resources and environment, surface engineering and materials science have developed rapidly, especially the combination of modern thermal spray technology and new nano-material, which supply a new structure protection layer for the parts surface that more strengthen, it can slow down the wear and corrosion process of the equipment, it has been widely applied for repairing and remanufacturing equipments, so improve the efficiency of resource regeneration utilizing.This work mainly elaborated the development process of thermal spraying technology and nano-materials, and its application in various fields, with the subject of TRT, start research on the application of nanometer spray technology in TRT blade pretreatment, and describes the process design, experimental research and industrial test of the whole process of the research of nano spray by focusing on the issue of corrosion and abrasion.Firstly, design the chemical composition of materials and structure of nano by analyzing the work condition and failure forms of the TRT, then selected the nano-material that containing Fe, Cr, C, B alloy elements, which can producing inter-metallic compounds and eutectic alloy with low melting point, it can strengthening the coating. Using the graded recombination structure of bottom and surface layer, which can reduce the internal stress of coating, improve the binding force between coating and metal base, enhanced abrasion resistance and corrosion resistance of the coating surface. Using plasma spraying to reduce the thermal effect on the substrate in the spraying process, and control the porosity of coating under 1%.Secondly, carrying out the experimental in the laboratory according to the designed technological, choosing the same material of 2Crl3 as the substrate, preparation several samples with different spraying technology parameters and coating material composition, then determine the optimum spraying technology parameters by analysis the physical and mechanical properties of the samples, the powder feed rate is 2.5 g·min-1, the spray distance is 110 mm, and the spraying speed is 800 mm·s-1.Lastly, conducting industrial experiments according to the lab results, after 6 months of application, there is no corrosion, scaling and obvious wear phenomena of the coating, and compare with the blade that without treatment and blade by laser welding and resin coating treatment, the blade which is treated with nano spray is better in the status of equipment and the unit operation efficiency, and it is fully meeting the demand of production.