Phase Transformation Behavior of Oxide Scale on Plain Carbon Steel Containing 0.4 wt.% Cr during Continuous Cooling

Li, Zhifeng; Cao, Guangming; Lin, Fei; Cui, Chunyuan; Wang, Hao; Liu, Zhenyu

doi:10.2355/isijinternational.isijint-2018-365

Cited by 19 publications

(5 citation statements)

References 33 publications

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“…These results indicate that, on the surface, FeO and Fe 3 O 4 also formed during the growth of FeCO 3 (at pH ∼ 7 and 80 °C) but they dissolved from the surface during the dissolution experiments at low pH, first Fe 3 O 4 , then FeO. These two minerals likely formed as byproducts of FeCO 3 from the de-carbonation of FeCO 3 , a process that increases the O 2 fugacity in the system as reported to occur in a small, although stable, field in the Fe-CO 2 -H 2 O system. , Furthermore, FeO likely formed first and then transformed to Fe 3 O 4 at pH near neutral and high temperature (at and above 80 °C) as previously reported. ,− …”

Section: Resultssupporting

confidence: 58%

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films

Matamoros-Veloza

Barker

Vargas

et al. 2021

ACS Appl. Mater. Interfaces

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Carbon steel is a universally used material in various transportation and construction industries. Research related to CO2 corrosion environments agree on the occurrence of siderite (FeCO3) as a main product conforming corrosion films, suggested to impart protection to carbon steel. Identifying and understanding the presence of all corrosion products under certain conditions is of greatest importance to elucidate the behavior of corrosion films under operation conditions (e.g., flow, pH, temperature) but information regarding the nature and formation of other Fe corrosion products apart from FeCO3 is lacking. Corrosion products in CO2 environments typically consist of common Fe minerals that in nature have been demonstrated to undergo transformations forming other Fe phases. This fact of nature has not been yet explored in the corrosion science field, which can help us to describe mechanisms associated to industrial processes. In this work, we present a multiscale and multidisciplinary approach to understand the mechanisms occurring on corrosion films under the key factors of flow and pH through the combination of molecular techniques with imaging. We report that certainly siderite (FeCO3, cylindrical with trigonalpyramidal caps) is the main product identified under the conditions used (representative of brine transport at 80C) but wustite (FeO) and magnetite (Fe3O4) minerals also form, likely from the de-carbonation of FeCO3 → FeO → Fe3O4, depending on pH under the action of flow. These minerals exist across the corrosion films evidencing a more complex nature of the three-dimensional layer not currently accounted in the mechanistic models. A relatively low flow velocity (1 m/s), as recognized for industrial operations, is enough to produce chemo-mechanical damage to the FeCO3 crystals causing breakage at low pH where dissolution of FeCO3 occurs with a rapid crystal size reduction of the cylindrical FeCO3 geometry of ~ 80% in just 8 hours changing also the local chemical structure of Fe3C under the film. Similarly, flow velocity of 1 m/s is capable to induce crystal removal at neutral pH inducing further degradation of the steel compromising the protectiveness assumption of FeCO3 corrosion films. The chemo-mechanical damage and Fe phase transformations will affect the critical localised corrosion and therefore, they need to be accounted for in mechanistic models aiming to find new avenues for control and mitigation of carbon steel corrosion.

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Section: Resultssupporting

confidence: 58%

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films

Matamoros-Veloza

Barker

Vargas

et al. 2021

ACS Appl. Mater. Interfaces

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“…From the calculated Gibbs free energies (Figure 18), chromium should oxidize first, then chromium spinels are formed, afterwards the oxidation of M 23 C 6 carbide starts, followed by the oxidation of iron and finally carbon. The oxidation of the carbides themselves has been reported by several authors [49][50][51][52][53]. It was found that M 23 C 6 carbides start to oxidize in the air atmosphere at elevated temperatures and thus can affect the oxidation kinetics, while MC carbides do not have a much effect on the oxidation kinetics.…”

Section: Discussionmentioning

confidence: 88%

High-Temperature Oxidation Behaviour of AISI H11 Tool Steel

Balaško

Vončina

Burja

et al. 2021

Metals

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The high-temperature oxidation of hot-work tool steel AISI H11 was studied. The high-temperature oxidation was investigated in two conditions, the soft annealed condition, and the hardened and tempered condition. First, calculations of the compositions of the oxide layers formed were carried out using the CALPHAD method. The samples were oxidised in a chamber furnace and in a simultaneous thermal analysis instrument, for 100 h in the temperature range between 400 °C and 700 °C. The first samples were used for metallographic (optical microscopy and scanning electron microscopy) and X-ray diffraction analysis of the formed oxide layers, and the second ones for the analysis of the oxidation kinetics by thermogravimetric analysis. Equations describing the high-temperature oxidation kinetics were derived. The kinetics can be described by three mathematical functions, namely: exponential, parabolic, and cubic. However, which function best describes the kinetics depends on the oxidation temperature and the thermal condition of the steel. Hardened and tempered samples have been shown to oxidise less, resulting in a slower oxidation rate. The oxide layers consist of three sublayers, the inner one being spinel-like oxide (Fe, Cr)3O4, the middle one a mixture of magnetite and hematite and the outer one of hematite. At 700 °C there is also some wüstite in the inner oxide sublayer of the soft annealed sample.

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“…Au addition suppresses the precipitation of magnetite seam and accelerates the eutectoid reaction. Li et al 15) found in their study that Cr in steel would form a Cr-rich layer at the oxide scale/matrix interface and replace the Fe 3 O 4 -seam layer, shortening the incubation period of eutectoid formation and significantly improving the transformation rate of FeO eutectoid reaction. In addition, the initial oxide scale structure retained after coiling also has a great influence on the FeO phase transformation behavior.…”

Section: Introductionmentioning

confidence: 99%

Isothermal Structure Transformation and Kinetics Behavior of Oxide Scale on Low Carbon Steel

et al. 2023

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The phase transformation of the oxide scale that forms on hot-rolled steel strips during cooling is one of the most important phenomena, which determines the surface quality of the strips, because the properties of the oxide scale, such as spallation resistance, crack initiation, and propagation, and pickling behavior, are strongly dependent on the oxide scale microstructure. To obtain steel strips with high surface quality, it is crucial to understand the microstructural development of the oxide scale. In this paper, a thermogravimetric analyzer was used to study the isothermal structure transformation behavior of FeO formed at high temperature in an inert gas (Ar) at 300-550°C for 1 000-15 000 s. Meanwhile, the isothermal dynamic model of FeO eutectoid transformation was established based on the JMAK equation combined with experimental data. The experimental results show that the oxide scale structure of the sample after pre-oxidation is composed of Fe 2 O 3 , Fe 3 O 4 , and FeO. At 300°C and 550°C, only the pro-eutectoid structure is formed in the oxide scale, but no eutectoid structure is formed. When the isothermal temperature is in the range of 350-500°C, both pro-eutectoid structure and eutectoid structure are formed in the oxide scale. With the extension of isothermal time, the eutectoid reaction continues until the complete decomposition of FeO. In addition, the FeO eutectoid transformation isothermal dynamics model was used to predict the eutectoid structure content of FeO eutectoid decomposition under different isothermal conditions, and the experimental data were compared with the predicted results, which verified the high prediction accuracy of the model.

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Phase Transformation Behavior of Oxide Scale on Plain Carbon Steel Containing 0.4 wt.% Cr during Continuous Cooling

Cited by 19 publications

References 33 publications

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films

High-Temperature Oxidation Behaviour of AISI H11 Tool Steel

Isothermal Structure Transformation and Kinetics Behavior of Oxide Scale on Low Carbon Steel

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Phase Transformation Behavior of Oxide Scale on Plain Carbon Steel Containing 0.4 wt.% Cr during Continuous Cooling

Cited by 19 publications

References 33 publications

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO3 Corrosion Films

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO3 Corrosion Films

High-Temperature Oxidation Behaviour of AISI H11 Tool Steel

Isothermal Structure Transformation and Kinetics Behavior of Oxide Scale on Low Carbon Steel

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Product

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Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO₃ Corrosion Films