The Oxidation of the HiSiMo Cast Irons Alloyed with Cr/Al at 800 °C

Zhu, Wenhui; Pint, Bruce A.; Huo, Yang; Godlewski, Larry; Ghaffari, Bita; Lekakh, Semen Naumovich; Engler-Pinto, Carlos; Li, Mei

doi:10.1007/s11085-022-10098-3

Cited by 2 publications

(1 citation statement)

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“…In addition, silicon enhances high temperature oxidation resistance by forming a silicon-rich oxide layer. The high-temperature oxidation behavior of SiMo nodular cast iron has been studied in dry air, wet air (air + 10% H 2 O), and exhaust gas environments at elevated temperatures (650 to 1050 • C) by many researchers [14][15][16][17][18][19][20][21]. These studies showed that when SiMo cast iron was exposed to high temperatures in the presence of air and exhaust gases (synthetic diesel and gasoline), it formed a multilayered oxide scale.…”

Section: Introductionmentioning

confidence: 99%

High Temperature Oxidation Behavior of High Al-Si Alloyed Vermicular Graphite Cast Iron for Internal Combustion Engine’s Hot-End Exhaust Components

Yilmaz,

Bayata,

Solak

2024

Metals

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This study investigated the influence of high silicon (4.2 wt%) and varying aluminum (3.5–4.8 wt%) content on the high temperature oxidation behavior and thermophysical properties of SiMoAl vermicular graphite cast iron for hot-end exhaust components. Isothermal oxidation tests at 800 °C and nonisothermal oxidation tests in a dry-air atmosphere were conducted on SiMo nodular iron, along with two SiMoAl vermicular graphite cast iron variants alloyed with 3.5 wt% Al and 4.8 wt% Al. The investigations revealed the formation of a thin duplex layer of oxide scale, consisting of an iron-rich external oxide layer and continuous aluminum oxide at the metal/oxide interface. Although aluminum oxide acted as a protective barrier by impeding the solid-state diffusion of oxygen, severe subsurface oxidation was observed due to the interconnected vermicular graphite covered by aluminum oxides after decarburization. Furthermore, based on nonisothermal oxidation experiments, the effective activation energy of oxidation was found to be significantly increased by the addition of aluminum, even though the oxidation activation energies of SiMoAl samples exhibited small changes in comparison to each other. Additionally, thermophysical analysis demonstrated a substantial decrease in the thermal conductivity and a slight increase in the thermal expansion with the addition of aluminum.

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