Steel Corrosion Mechanisms

Bloom, M. C.; Newport, G. N.; Fraser, W. A.

doi:10.1149/1.2426000

Cited by 22 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The definition of quantities and the method of estimation are as follows: First, the sum of the amount of Fe ions in the oxide (W F ) and the amount of Fee , ions dissolved into the water (W 0 ) is the total amount of iron (6) autoclave (type 316), (7) heating system, (8) sample, (9) thermocouple system, (10) cooler, (11) pressure gauge, (12) filter, (13) leak valve, (14) piping system (type 316).…”

Section: Corrosion Rate Measurementmentioning

confidence: 99%

Effect of Temperature and Dissolved Oxygen on the Corrosion Behavior of Carbon Steel in High-Temperature Water

Mabuchi

Horn²,

Takahashi

et al. 1991

Corrosion

View full text Add to dashboard Cite

The corrosion behavior of carbon steel in high-temperature water, and the structure and composition of the oxide film were examined as functions of dissolved oxygen concentration (DO), temperature (T), and corrosion time (t). The total amount of iron corroded (WT) was differentiated into the amounts of iron ions in the oxide (WF) and dissolved into the water (WD). The total rate of corrosion (rT), the rate of iron dissolution (ru), and the rate of accumulation of iron in the oxide (r,) were obtained by differentiating the time variations in W, WF, and Wo.°S The structure and composition of the oxide film were examined by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and transmission and scanning electron microscopy. In general, r T increases with increasing DO and T, r, shows T-and DO-dependent minimum, and there is serious localized corrosion at high DO above 500 ppb. Oxide films consist of magnetite except at T = 60°C, DO = 50 to 200 ppb where a thin layer of hydrous ferric oxide is formed. At DO = 500 ppb, the outermost part of the magnetite changes into y-Fe2O3, and above DO = 1.0 ppm, appreciable amounts of a-Fe203 cover the magnetite oxide layer. The rT and rD valuesare not related to the presence of yFe2O3 or Fe3O4 in the surface structure of the oxide, but clearly decrease as the OH/Fe mole ratio at the oxide surface increases. The mechanism determining the corrosion rate changes is discussed.

show abstract

Section: Corrosion Rate Measurementmentioning

confidence: 99%

Effect of Temperature and Dissolved Oxygen on the Corrosion Behavior of Carbon Steel in High-Temperature Water

Mabuchi

Horn²,

Takahashi

et al. 1991

Corrosion

View full text Add to dashboard Cite

show abstract

“…Research initiated by Potter (1) in England and Bloom (2) in the United States has shown that the morphology of iron oxide films generated on steel by attack of high temperature NaOH solution is apparently dependent on the physical system employed. Static corrosion tests at these two laboratories using alkali solutions of similar composition and run at the same temperatures produce oxide films which are chemically the same (Fe304), but structurally different.…”

mentioning

confidence: 99%

Growth Characteristics of Iron Oxide Films Generated in Dilute Lithium Hydroxide Solution at 300°C

Moore

Jones²

1968

J. Electrochem. Soc.

View full text Add to dashboard Cite

In the early stages of iron oxide growth on mild steel in pH 11 normalLiOH solution at 300°C, the oxide is largely oriented and grows at a rate and with a morphology dependent on the substrate grain orientation. After a certain film thickness is attained, however, the epitaxial oxide growing in the (001) Fe3O4//false(001false)α‐normalFe , false[1true1¯0false]Fe3O4//false[100false]α‐normalFe orientation degenerates, leaving in its place a much thinner, fine‐grained, randomly oriented “base film” partially covered by large solution‐grown Fe3O4 crystals. Experimental evidence indicates that the transformation is induced by stress generated within the epitaxial oxide as the film thickens. The two‐phased oxide structure which exists after completion of the epitaxial oxide degeneration persists through oxidation periods of up to at least 300 hr. Observations of its growth behavior lead to the postulation of a growth mechanism in which iron passes through the base film into solution, subsequently to precipitate forming the upper surface crystals. It is shown possible, using this hypothesis, to derive a theoretical rate law which predicts that, in agreement with the experimentally determined corrosion rate data, the corrosion rate should decrease in a logarithmic fashion.

show abstract

“…In recent years (1)(2)(3)(4)(5)(6), studies h a v e been made of the growth of protective magnetite films on mild steel in alkaline solutions at typical operating temperatures in order to establish their properties and to throw some light upon the occasional circumstances in which they lose their protective character and produce a rapid pitting attack.…”

mentioning

confidence: 99%

The Morphology of Magnetite Growth on Mild Steel in Alkaline Solutions at 316°C

Marsh

1966

J. Electrochem. Soc.

View full text Add to dashboard Cite

In previous work on the oxidation of mild steel to magnetite in high‐temperature alkaline solutions different workers have obtained markedly differing types of oxide under apparently similar conditions. The types of oxide obtained, the conditions under which they were grown, and possible reasons for the difference in oxide morphology are discussed. Experiments are described which support the idea that the type of magnetite growth obtained upon an area of mild steel depends upon the presence or otherwise of a suitable cathodic surface in contact with it. For example, the oxidation of a mild steel specimen in a new pressure vessel will take place in a different manner to that of a specimen in a vessel with a pre‐formed protective magnetite film coating its sides, since the magnetite film in the latter case probably acts as a cathode for the oxidation of the specimen. The properties of the types of growth, and in particular their healing properties, are discussed with particular reference to the practical problem of pitting growth in steam generator tubes.

show abstract

Steel Corrosion Mechanisms

Cited by 22 publications

References 6 publications

Effect of Temperature and Dissolved Oxygen on the Corrosion Behavior of Carbon Steel in High-Temperature Water

Effect of Temperature and Dissolved Oxygen on the Corrosion Behavior of Carbon Steel in High-Temperature Water

Growth Characteristics of Iron Oxide Films Generated in Dilute Lithium Hydroxide Solution at 300°C

The Morphology of Magnetite Growth on Mild Steel in Alkaline Solutions at 316°C

Contact Info

Product

Resources

About