Active screen plasma nitriding of 316 stainless steel for the application of bipolar plates in proton exchange membrane fuel cells

摘要

Proton exchange membrane fuel cell (PEMFC) has attracted considerable interest because\udof its superb performance, and many researches are focused on the development of highperformance,\udlong-life bipolar plates. Stainless steel bipolar plates offer many advantages\udover the conventional graphite bipolar plates, such as low material and fabrication cost,\udexcellent mechanical behaviour and ease of mass production. However, the insufficient\udcorrosion resistance and relatively high interfacial contact resistance (ICR) become the\udmajor obstacles to the widespread use of stainless steel bipolar plates. In this work, active\udscreen plasma nitriding (ASPN), a novel plasma nitriding technique, was used to modify\udthesurfaceof316austeniticstainlesssteel.Avarietyofanalyticaltechniques,includingXraydiffraction(XRD),scanningelectronmicroscopy(SEM),glowdischargeopticalemission\udspectrometer (GDOES), were employed to characterize the nitrided samples. The results\udreveal thatanitrogen supersaturated S-phase layerhasbeensuccessfully produced onthe\udsurface of all nitrided 316 stainless steel samples. The interfacial contact resistance (ICR)\udvaluecanbedecreaseddramaticallyafterASPNtreatmentandthecorrosionresistancecan\udalso been improved. In addition, better corrosion resistance can be achieved by active\udscreen plasma nitriding with a stainless steel screen than with a carbon steel screen. This\udtechnique could beusedtoimprovetheperformanceand lifespan ofbipolar platesforfuel\udcells.