磁力研磨法去除燃油喷嘴积碳的试验研究

针对燃油喷嘴大修再制造中积碳难去除的问题。利用扫描电子显微镜（SEM）分析喷嘴表面积碳的微观形貌和成分组成，为磁力研磨技术去除积碳方法的确定和工艺研究奠定基础。从旋转磁场的产生原理、磁针在磁场中受力和磁针在磁场中运动三方面综合分析了磁力研磨法的材料去除机理。采用电磁研磨装置对喷嘴进行积碳去除试验，运用响应面分析法分析旋转磁场转速、磁针的型号尺寸和研磨时间的交互作用对材料去除量和表面粗糙度的影响规律，确定试验的最佳工艺参数。最优的工艺参数为：磁针型号尺寸Ø0.8 mm×5 mm，旋转磁场转速1 000 r/min，研磨时间40 min。通过微观形貌的观测以及表面应力检测分析，综合评价研磨后的喷嘴表面质量。结果表明，研磨后的喷嘴表面积碳基本去除，表面光滑，残余应力明显下降，金相组织完好。经过专业测试，研磨后的残余积碳小于技术要求规定值。采用磁力研磨技术，可以有效去除燃油喷嘴表面积碳，去除效率高，技术环保，满足绿色再制造的要求。

Experimental study on removing carbon from fuel nozzles by magnetic grinding

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.