上海交通大学学报

上海交通大学学报（自然版） ›› 2019, Vol. 53 ›› Issue (2): 247-252.doi: 10.16183/j.cnki.jsjtu.2019.02.017

• 学报（中文） • 上一篇    

奥氏体不锈钢双极板的低温超饱和气体渗碳表面改性

姜勇，李洋，周阳，巩建鸣   

  1. 南京工业大学 机械与动力工程学院； 极端承压装备设计与制造重点实验室， 南京 211816
  • 出版日期:2019-02-28 发布日期:2019-02-28
  • 作者简介:姜勇(1974-)，男，山东省乳山市人，副教授，主要研究方向为金属材料表面改性和性能分析. 电话(Tel.)：025-58139362；E-mail: jiangyong@njtech.edu.cn.
  • 基金资助:
    国家自然科学基金(51475224)，江苏省高校自然科学研究重大项目(14KJA470002)，江苏省普通高校研究生创新计划(CXZZ11_0420)

Surface Modification of Austenitic Stainless Steel Bipolar Plates by Low Temperature Colossal Supersaturation Gaseous Carburization

JIANG Yong,LI Yang,ZHOU Yang,GONG Jianming   

  1. College of Mechanical and Power Engineering; Key Laboratory of Design and Manufacture of Extreme Pressure Equipment, Nanjing Tech University, Nanjing 211816, China
  • Online:2019-02-28 Published:2019-02-28

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摘要： 通过低温超饱和气体渗碳(LTCSGC)处理，在316L不锈钢双极板表面形成了一层厚度约30 μm的渗碳层，研究了从基体沿渗碳层深度方向的碳的质量分数、残余应力、硬度分布和相结构，测量了渗碳后316L不锈钢双极板的接触电阻，分析了渗碳后316L不锈钢双极板在模拟质子交换膜燃料电池(PEMFC)环境中的耐腐蚀性能.结果表明：渗碳层是由膨胀奥氏体相组成的梯度材料，从渗碳层表面到基体的碳的质量分数、残余应力和硬度逐渐降低；经过LTCSGC处理后，316L不锈钢双极板的接触电阻降低了34%；在模拟PEMFC的阳极环境中，其自腐蚀电位升到 -79mV，高于工作电位 -0.1V，获得了阴极保护；在模拟PEMFC的阴极环境中，其自腐蚀电位提高了260mV，抗腐蚀性能显著提高，恒电位极化腐蚀电流密度降低了75%.

关键词: 质子交换膜燃料电池, 奥氏体不锈钢, 双极板, 低温超饱和气体渗碳, 抗腐蚀性能

Abstract: By the means of low temperature colossal supersaturation gaseous carburization (LTCSGC) technique, a carburizing layer of 30 μm was formed on the surface of 316L austenitic stainless steel bipolar plate. The carbon concentration, compressive residual stress, nano-hardness and the phase structure along cross-sectional depth direction of the specimens were investigated, respectively. Besides, the contact resistance of carburized 316L stainless steel bipolar plates was measured and the corrosion resistance of the samples in simulated proton exchange membrane fuel cell (PEMFC) environment was analyzed. Results demonstrate that the LTCSGC layer was a functionally gradient material which was composed of expanded austenite. Moreover, its carbon concentration, residual stress and hardness decline continuously along cross-sectional depth direction from surface to substrate. Compared with 316L stainless steel bipolar plates, the contact resistance of carburized samples after LTCSGC treatment was reduced by 34%. The self-corrosion potential in PEMFC anode environment was improved to -79mV, which was higher than the PEMFC work potential (-0.1V). Therefore, it was protected by cathode. In PEMFC simulated cathode environment, the self-corrosion potential was increased by 260mV and the corrosion resistance was remarkably improved. Meanwhile, the potentiostatic polarization etching current density was reduced by 75%.

Key words: proton exchange membrane fuel cell (PEMFC), austenitic stainless steel, bipolar plate, low temperature colossal supersaturation gaseous carburization (LTCSGC), corrosion resistance

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