Abstract: This paper focuses on the problem of removing carbon deposition from a flame nozzle in the remanufacturing process. The magnetic needle grinding technology is selected as the method to remove carbon deposition due to its micro topography and components analyzed by Scanning Electron Microscope (SEM). Based on the removing process, an electromagnetic grinding equipment is chosen to conduct the removing test. To find the optimal process parameters for the test, a response surface analysis is adopted to analyze the influence law on the removal amount and surface roughness by the interactions between every two of the three following parameters, including rotational speed of rotating magnetic field, needle type, and grinding time. By comprehensively considering the test results, the optimal parameters can be obtained at the rotational speed of 1 000 r/min, the needle type Ø0.8 mm×5 mm, and the grinding time 40 min. The surface quality of the nozzle can be evaluated by observing the micro topography and testing the surface stress. After grinding, the nozzle surface is smooth with little carbon deposition, and the metallographic structure is in good condition with significant decrease of residual stress.Professional tests show that the remaining carbon deposition amount on the nozzle surface is less than the specified value required by the technology. The magnetic needle grinding technology, which can effectively remove carbon deposition off the flame nozzle with high efficiency, meeting the requirements of environmental friendliness and green remanufacturing.

Key words: nozzle, remanufacturing, carbon deposition, magnetic abrasive finishing, surface roughness