Research on the Oxidation Mechanism of Vermicular Graphite Cast Iron

Guo, Qiaoqin; Yang, Zhong; Guo, Ding; Dong, Tao; Guo, Ya-Fang; Li, Jianping; Bai, Yaping

doi:10.3390/ma12193130

Cited by 13 publications

(7 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Ref. [12], Fe 2 O 3 is flaky and needle-like, Fe 3 O 4 is blocky, and in the oxidation process, the oxide layer of RuT400 mainly consists of FeO, Fe 2 O 3 , Fe 3 O 4 , and Fe 2 SiO 4 .…”

Section: Morphology Of the Oxide Layermentioning

confidence: 99%

See 1 more Smart Citation

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

Chen

Pang

et al. 2021

Acta Metall. Sin. (Engl. Lett.)

View full text Add to dashboard Cite

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.

show abstract

Section: Morphology Of the Oxide Layermentioning

confidence: 99%

“…At present, researches on the oxidation of VGI involve many aspects. Guo et al [12] studied the oxidation mechanism of VGI at 530 °C. They observed that the oxidation reaction started from the vermicular graphite and diffused from the outside to the inside.…”

Section: Introductionmentioning

confidence: 99%

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

Chen

Pang

et al. 2021

Acta Metall. Sin. (Engl. Lett.)

View full text Add to dashboard Cite

show abstract

“…After the oxidation of graphite, voids or pores are developed that lead to oxygen penetration inside the metal matrix, causing subsurface oxidation. Lin et al [29] and Guo et al [30] demonstrated that flake graphite and vermicular graphite cast irons had worse hightemperature oxidation resistance compared to nodular cast iron due to severe subsurface oxidation. Since graphite flakes were almost interconnected to each other, they served as the primary core and pathway for oxidation.…”

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

View full text Add to dashboard Cite

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.

show abstract

“…Therefore, they are more suitable for manufacturing large and medium-sized engines. However, the high tensile strength of CGI means that machining requires greater cutting force, high toughness makes it difficult to remove metal and low thermal conductivity leads to difficult heat dissipation and short service life of tools [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Tool Coatings on Machining Properties of Compacted Graphite Iron

Tan

et al. 2022

Micromachines

View full text Add to dashboard Cite

Compacted graphite iron (CGI) has become the most ideal material for automotive engine manufacturing owing to its excellent mechanical properties. However, tools are severely worn during processing, considerably shortening their lifespan. In this study, we prepared a series of cemented carbide-coated tools and evaluated their coating properties in cutting tests. Among all tested coatings, PVD coating made of AlCrN (AC) presented with the best surface integrity and mechanical properties, achieving the best comprehensive performance in the coating test. The AC-coated tool also exhibited the best cutting performance at a low speed of 120 m/min, corresponding to a 60% longer cutting life and the lowest workpiece surface roughness relative to other coated tools. In the cutting test at a high speed of 350 m/min, the CVD double-layer coated tool (MT) with a TiCN inner layer of and an Al2O3 outer layer had a 70% longer cutting life and the lowest workpiece surface roughness relative to other coated tools.

show abstract

Research on the Oxidation Mechanism of Vermicular Graphite Cast Iron

Cited by 13 publications

References 27 publications

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

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

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

Effect of Tool Coatings on Machining Properties of Compacted Graphite Iron

Contact Info

Product

Resources

About