High-Temperature Oxidation Behavior and Related Mechanism of RuT400 Vermicular Graphite Iron

• Published in: Acta metallurgica sinica : English letters 2022-07, Vol.35 (7), p.1117-1130
• Main Authors: Chen, Yu, Pang, Jian-chao, Li, Shou-xin, Zhang, Zhe-feng
• Format: Article
• Language: English
• Subjects: Aluminum alloys; Cast iron; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Crack propagation; Cylinder heads; Diesel engines; Experiments; Graphite; Heat conductivity; High temperature; Materials Science; Metallic Materials; Microstructure; Nanotechnology; Organometallic Chemistry; Oxidation; Pearlite; Reaction kinetics; Scanning electron microscopy; Spectroscopy/Spectrometry; Temperature; Thermal cycling; Thickness; Tribology
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-021-01343-w

The vermicular graphite iron is an important material with excellent combination properties for cylinder heads of diesel engines, and the high-temperature oxidation is a crucial problem during service of the component. In this study, the oxidation experiment of RuT400 vermicular graphite iron was performed at 500 °C, and the oxidation time was chosen as 100 h, 200 h, 300 h, 400 h, and 500 h, respectively. Meanwhile, the corresponding microstructure evolution, oxidation kinetics, and oxidation mechanism were discussed. It is found that oxidation pores and oxide layer often appear at the vermicular graphite on the specimen surface; the vermicular graphite plays the role of oxidation channel, and it tends to diffuse along the adjacent pearlite and then connect with each other to form oxidation bridges as the oxidation time prolongs. A linear relationship between oxidation weight gain and the thickness of the oxide layer was established and verified well. These results will give a more comprehensive understanding on the oxidation mechanism of vermicular graphite iron and provide certain guidance for design and preparation of anti-oxidation cast irons.