Mao Jingwen, Wang Enhua, Chen Youpeng, Liu Yadi, Wang Hewu, Ouyang Minggao, Hu Haoran, Lu Languang, Ren Dongsheng
School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Beijing Swift New Energy Technologies Co., Ltd., Beijing, 100192, China.
Heliyon. 2024 Jun 20;10(12):e33245. doi: 10.1016/j.heliyon.2024.e33245. eCollection 2024 Jun 30.
Selecting adequate ferritic stainless steel (FSS) with a high corrosion resistance and a low cost is critical for solid oxide fuel cells (SOFCs) operating at intermediate temperature. In this study, the corrosion behaviors of four commercial FSSs involving TS430, TY441, YG442, and TY445 with a Cr content ranging from 16.18 wt.% to 21.73 wt.% are investigated at 650 °C. The oxidation mass gains, microstructures of surface oxide scale, and electrical conductivities are measured. The effects of grain size as well as doped elements are estimated together with the Cr volatilization. Flaky CrO particles are formed on TS430 and TY441 dominated by the outward migration of Cr. In comparison, a thin and dense layer of chromia is observed on YG442 and TY445. A high Cr content and a uniformly distributed grain size are conducive to the formation of a thin and dense chromia scale on the FSS surface during the initial oxidation process. On the other hand, the addition of Nb, Ti, and Mo weakens the outward diffusion of Cr and reduces the particle size of chromia. After oxidation at 650 °C for 120 h, scattered (Mn, Cr)O spinel particles occur on TS430, YG442, and TY445. TY445 and YG442 exhibit a higher conductivity although all the results of area specific resistance (ASR) are less than 6 mΩ·cm. Meanwhile, the effect of Cr volatilization is enlarged on the estimation of mass gain at 650 °C compared with even higher temperatures.
选择具有高耐腐蚀性和低成本的合适铁素体不锈钢（FSS）对于在中温下运行的固体氧化物燃料电池（SOFC）至关重要。在本研究中，研究了四种商业FSS（TS430、TY441、YG442和TY445，Cr含量范围为16.18 wt.%至21.73 wt.%）在650°C下的腐蚀行为。测量了氧化质量增益、表面氧化膜的微观结构和电导率。结合Cr挥发评估了晶粒尺寸以及掺杂元素的影响。在TS430和TY441上形成了片状CrO颗粒，这主要是由Cr的向外迁移主导的。相比之下，在YG442和TY445上观察到一层薄而致密的氧化铬层。高Cr含量和均匀分布的晶粒尺寸有利于在初始氧化过程中在FSS表面形成薄而致密的氧化铬膜。另一方面，添加Nb、Ti和Mo会削弱Cr的向外扩散并减小氧化铬的颗粒尺寸。在650°C氧化120小时后，TS430、YG442和TY445上出现了分散的（Mn，Cr）O尖晶石颗粒。尽管所有面积比电阻（ASR）结果均小于6 mΩ·cm，但TY445和YG442表现出更高的电导率。同时，与更高温度相比，在650°C下Cr挥发对质量增益估计的影响更大。
