316L不绣钢双极板表面Cr及氮化物涂层的制备与性能
发布时间：2019-05-28 10:42
【摘要】：质子交换膜燃料电池(PEMFC)由于有着诸多优越的性能,被认为是未来应用前景最好和市场发展最重要的一种发电装置。双极板是承载着PEMFC重要功能的核心部件之一,占据了电池组绝大部分的重量及成本。与现有的石墨类双极板材料相比,金属类材料在抗气体渗透能力、机械强度、规模化生产加工及提高电池的比功率等方面的优势明显,但金属双极板的腐蚀问题一直是制约其应用发展的重要因素。本文主要研究了在316L不锈钢板表面磁控溅射铬涂层的沉积工艺,并对涂层腐蚀性能进行了研究；探索Cr涂层表面熔盐电化学氮化机制,先在熔盐体系中对不锈钢双极板表面进行电化学氮化研究,为在316L不锈钢表面制备出性能优异的Cr/CrxN涂层奠定研究基础。采用直流磁控溅射技术在316L不锈钢双极板表面沉积Cr涂层,利用扫描电镜对316L不锈钢表面镀Cr涂层进行微观形貌观察和分析,结果表明：当溅射电流由0.2A增加到0.25A时,涂层的表面晶粒尺寸增加；随着沉积时间的延长,316L/Cr涂层更均匀致密。溅射不同时间的316L/Cr涂层在0.5mol/L H2SO4溶液中浸泡进行电化学测试得知：随着溅射沉积时间增加,腐蚀电位变大,腐蚀电流密度会减小；溅射电流为0.25A、时间为3h的316L/Cr涂层在腐蚀溶液中浸泡768h后,其腐蚀电位仍保持较高,涂层仍保持很好稳定性,能有效抑制基体合金的腐蚀。在LiCl-KCl-KNO2熔盐体系中,采用电化学方法对316L不锈钢表面进行氮化工艺研究。首先利用循环伏安法分析确定氮沉积电位,再采用恒电位法在316L不锈钢表面沉积氮涂层。结果表明：在UCl-KCl-KNO2体系中的电化学氧化还原中,N3+还原成N的电位明显低于Li和K离子还原成相应碱金属的电位；熔融LiCl-KCl-lmol%KNO2体系中,在480℃时N3+还原成N原子并渗入不锈钢表面。渗氮层均匀致密,厚度约为10μm。
[Abstract]:Proton exchange membrane fuel cell (PEMFC) is considered to be the most important power generation device with the best application prospect and market development because of its excellent performance. Bipolar plate is one of the core components that carry the important function of PEMFC, which accounts for most of the weight and cost of battery pack. Compared with the existing graphite bipolar plate materials, metal materials have obvious advantages in gas permeability, mechanical strength, large-scale production and processing and increasing the specific power of batteries. However, the corrosion of metal bipolar plate has always been an important factor restricting its application and development. In this paper, the deposition process of magnetron splashing chromium coating on 316L stainless steel plate was studied, and the corrosion properties of the coating were studied. To explore the electrochemical nitriding mechanism of molten salt on the surface of Cr coating, the electrochemical nitriding of stainless steel bipolar plate was studied in molten salt system, which laid a foundation for the preparation of Cr/CrxN coating with excellent properties on 316L stainless steel surface. Cr coating was deposited on 316L stainless steel bipolar plate by DC magnetron sputter. The microstructure of Cr coating on 316L stainless steel surface was observed and analyzed by scanning electron microscope (SEM). The results showed that when the sputtering current increased from 0.2A to 0.25A, the coating was deposited on the surface of 316L stainless steel by scanning electron microscope (SEM). The surface grain size of the coating increases. With the prolongation of deposition time, 316L/Cr coating is more uniform and compact. The 316L/Cr coatings deposited in 0.5mol/L H2SO4 solution for different time were immersed in 0.5mol/L H2SO4 solution. The results showed that with the increase of deposition time, the corrosion potential increased and the corrosion current density decreased. After soaking the 316L/Cr coating in corrosion solution for 768 h with a sputter current of 0.25 A and a time of 3 h, the corrosion potential of the coating is still high and the coating is still stable, which can effectively inhibit the corrosion of the matrix alloy. The nitriding process of 316L stainless steel surface was studied by electrochemical method in LiCl-KCl-KNO2 molten salt system. Firstly, the nitrogen deposition potential was determined by cyclic volt-ampere method, and then the nitrogen coating was deposited on the surface of 316L stainless steel by potentiostatic method. The results show that in the electrochemical redox of UCl-KCl-KNO2 system, the potential of N _ 3 reduction to N is significantly lower than that of Li and K ions to the corresponding alkali metal. In the molten LiCl-KCl-lmol%KNO2 system, N _ 3 is reduced to N atom at 480 鈩，
本文编号：2486987
[Abstract]:Proton exchange membrane fuel cell (PEMFC) is considered to be the most important power generation device with the best application prospect and market development because of its excellent performance. Bipolar plate is one of the core components that carry the important function of PEMFC, which accounts for most of the weight and cost of battery pack. Compared with the existing graphite bipolar plate materials, metal materials have obvious advantages in gas permeability, mechanical strength, large-scale production and processing and increasing the specific power of batteries. However, the corrosion of metal bipolar plate has always been an important factor restricting its application and development. In this paper, the deposition process of magnetron splashing chromium coating on 316L stainless steel plate was studied, and the corrosion properties of the coating were studied. To explore the electrochemical nitriding mechanism of molten salt on the surface of Cr coating, the electrochemical nitriding of stainless steel bipolar plate was studied in molten salt system, which laid a foundation for the preparation of Cr/CrxN coating with excellent properties on 316L stainless steel surface. Cr coating was deposited on 316L stainless steel bipolar plate by DC magnetron sputter. The microstructure of Cr coating on 316L stainless steel surface was observed and analyzed by scanning electron microscope (SEM). The results showed that when the sputtering current increased from 0.2A to 0.25A, the coating was deposited on the surface of 316L stainless steel by scanning electron microscope (SEM). The surface grain size of the coating increases. With the prolongation of deposition time, 316L/Cr coating is more uniform and compact. The 316L/Cr coatings deposited in 0.5mol/L H2SO4 solution for different time were immersed in 0.5mol/L H2SO4 solution. The results showed that with the increase of deposition time, the corrosion potential increased and the corrosion current density decreased. After soaking the 316L/Cr coating in corrosion solution for 768 h with a sputter current of 0.25 A and a time of 3 h, the corrosion potential of the coating is still high and the coating is still stable, which can effectively inhibit the corrosion of the matrix alloy. The nitriding process of 316L stainless steel surface was studied by electrochemical method in LiCl-KCl-KNO2 molten salt system. Firstly, the nitrogen deposition potential was determined by cyclic volt-ampere method, and then the nitrogen coating was deposited on the surface of 316L stainless steel by potentiostatic method. The results show that in the electrochemical redox of UCl-KCl-KNO2 system, the potential of N _ 3 reduction to N is significantly lower than that of Li and K ions to the corresponding alkali metal. In the molten LiCl-KCl-lmol%KNO2 system, N _ 3 is reduced to N atom at 480 鈩，
本文编号：2486987
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