Carbon steel rusting affects the carbon content within the metal matrix
the verdict
INSUFFICIENT LEANING
refutedsupported
the weight of evidence
2 sources for · 0 against
The retrieved literature touches on carbon steel matrix dissolution and galvanic interaction between phases during corrosion, but does not provide complete evidence detailing the exact fate of carbon within the metal matrix.
Purpose
This study aims to investigate the crevice corrosion behavior of carbon steel in neutral/alkaline environments utilizing a transient multi-physics field model.
Design/methodology/approach
The crevice corrosion of carbon steel with different solution pH and crevice width was modeled, incorporating mass transfer, homogeneous phase and localized electrochemical reactions. The extent of crevice corrosion was evaluated by the geometric deformation of the model mesh. The hydro-chemical state inside the crevice was discussed through the Cl− concentration and potential distribution of the solution.
Findings
Results revealed that the formation of pitting corrosion near the crevice mouth was accelerated in a neutral solution. When pH = 8 and pH = 9, the carbon steel matrix was dissolved and the Cl− content within the solution was significantly reduced due to the higher concentration of hydroxide ions (OH−).
Originality/value
The crevice corrosion behavior of carbon steel in neutral/alkaline environments is closely associated with solution pH rather than the crevice width. The inhibition of crevice corrosion in alkaline environments was proved by finite element simulation. These findings provide valuable insights that can be applied in engineering applications to prevent and mitigate crevice corrosion in neutral/alkaline environments.
# What happens to the carbon in carbon steel when it rusts?
- Tags: oxidation-state, metallurgy, carbon-allotropes, corrosion
- Score: 9
- Views: 1,075
- Answers: 1
- Asked by: Gimelist (5,557 rep)
- Asked on: Jun 24, 2019
- Last active: Jun 25, 2019
- License: CC BY-SA 4.0
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## Question
Carbon steel is iron containing some carbon in various forms of iron carbide.
When it rusts (oxidises), the iron becomes part of all kinds of crystalline and amorphous iron oxides and hydroxides, mostly as Fe3+.
Where does the carbon go in this process? Does it also oxidise to carbon dioxide or monoxide and leaves the system as a gas? Does it combine with the iron to form siderite (iron carbonate)? Does it remain as graphite or some other form of elemental carbon? Something else?
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## Accepted Answer — Score: 9
- By: DrMoishe Pippik (40,152 rep)
- Answered on: Jun 25, 2019
Cast iron has considerable free carbon as graphite, but [carbon steel](https://en.wikipedia.org/wiki/Carbon_steel) has iron carbide in cementite, $\\ce{Fe3C}$ in a ferrite ($\\ce{α-F}$e) matrix, along with other phases and additives. In a corrosive environment, the ferrite and cementite form a galvanic couple, causi
Everything we examined (2)
This check searched the claim as stated. It did not run a separate search for evidence against it.