High-density plasma nitriding of AISI 316L for bipolar plate in proton exchange membrane fuel cell

✍ Scribed by Wonhyuk Hong; Dong-Hoon Han; Hyoseok Choi; Min-Woo Kim; Jung-Joong Lee

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 675 KB
• Volume: 36
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.11.077

✦ Synopsis

Austenitic stainless steel (AISI 316L) is nitrided by inductively coupled plasma using a gas mixture of N 2 and H 2 at temperatures between 530 K and 650 K, and the corrosion resistance as well as the interfacial contact resistance (ICR) are measured in a simulated proton exchange membrane fuel cell (PEMFC) environment.

After plasma nitriding, a nitrogen-expanded austenite layer, the so-called S-phase is formed in all nitrided samples. The ICR value of the nitrided samples decreases to approximately 10 mUcm 2 after plasma nitriding. The sample nitrided at 590 K shows the best corrosion property, while the corrosion resistance of the sample nitrided at higher temperatures decreases because of the formation of Cr-depleted regions in the nitrided sample. By using high-density plasma, the process temperature can be reduced to such a low temperature that Cr depletion is not significant, but a dense S-phase is formed.