1.内燃机可靠性国家重点实验室，山东 潍坊 261061；
2.潍柴动力空气净化科技有限公司，山东 潍坊 261061
Abstract：The influence of material corrosion of aftertreatment system on catalyst performance is studied. Taking the NOx conversion efficiency as the evaluation indicator, the effect of material corrosion of the aftertreatment system on catalyst performance is analyzed through bench performance test, catalyst sample test analysis, electron microscope scanning and X-ray energy spectrum analysis of the sample of the problem aftertreatment system, and the material is optimized through stainless steel material performance analysis and bench corrosion resistance test. The analysis results show that the NOx conversion efficiencies of the inlet and outlet ends of the first stage A-SCR catalyst along the gas flow direction are inconsistent, and the iron corrosion of the inlet of the catalyst leads to the decrease of the NOx conversion efficiency of the catalyst. There is little difference between the NOx conversion efficiency of the second stage B-SCR and the third stage C-SCR/ASC catalysts and the performance of the fresh samples. The results of electron microscope scanning and energy dispersive X-ray analysis show that Fe, Ni and other elements are found on the inlet of the first stage A-SCR catalyst, and corrosion is the main factor for the reduction of NOx conversion efficiency of the catalyst, not high temperature degradation. The results of performance analysis of stainless steel and corrosion resistance test on the bench show that SUS444 stainless steel has good corrosion resistance and meets the requirements of key parts.
Keywords:aftertreatment system; material corrosion; catalyst; NOx conversion efficiency; bench test