Rust Layer

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Junhua Dong - One of the best experts on this subject based on the ideXlab platform.

  • insight into atmospheric corrosion evolution of mild steel in a simulated coastal atmosphere
    Journal of Materials Science & Technology, 2021
    Co-Authors: Junhua Dong, Yue Wang, Aniefiok Joseph Umoh
    Abstract:

    Abstract The corrosion behavior of mild steel in a simulated coastal atmosphere environment has been investigated by the indoor accelerated wet/dry cyclic corrosion acceleration test (CCT), scanning electron microscopy (SEM), Raman spectroscopy and electrochemical measurements. During the CCT test of 60 cycles, the evolution of logarithmic (corrosion rate) vs. logarithmic (CCT cycles) presents a turning point at the 5th cycle, presenting a tendency to increase first and then decrease to gradually stabilize as the CCT cycle prolonged. Before the 5th cycle, γ-FeOOH and β-FeOOH and Fe3O4 were detected, respectively. And then, α-FeOOH as a new chemical composition was detected in the subsequent corrosion cycles. It is found that, after long term corrosion, the Rust separated into a relatively dense inner Layer rich with α-FeOOH and a loose outer Layer rich with γ-FeOOH, both of which have poor electrical conductivity. The rapid increase of corrosion rate in the early stage since reducible corrosion products are involved in the reduction process of the cathode which promotes the dissolution of the anodic metal substrate. Afterward, as the Rust Layer thickens, the resistance of the Rust increases, and the aggressive ions diffusion is blocked, gradually suppressing the electrochemical corrosion process. At last, when the composition and distribution of the Rust Layer remain stable, the corrosion presents a fluctuating speed around a certain value during the cracking and self-repairing process of the Rust Layer.

  • atmospheric corrosion monitoring of a weathering steel under an electrolyte film in cyclic wet dry condition
    Corrosion Science, 2014
    Co-Authors: Ch Thee, Junhua Dong, Xin Mu, Xiaofang Li, Wei Ke
    Abstract:

    Abstract Electrochemical Impedance Spectroscopy (EIS) and film thickness measurements have been employed to study the corrosion monitoring of steel under an electrolyte film in wet–dry cycles simulating a coastal atmosphere. The results indicate that within each cycle, the corrosion rate increases during drying process due to an increase in Cl − concentration and an enhancement of oxygen diffusion by thinning out of the electrolyte. As corrosion process proceeds, the corrosion rate increases greatly and reaches a maximum. During subsequent corrosion stage, the corrosion rate decreases greatly and keeps at a low value due to the formation of a stable Rust Layer.

  • Rusting evolution of mncup weathering steel submitted to simulated industrial atmospheric corrosion
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2012
    Co-Authors: Long Hao, Sixun Zhang, Junhua Dong
    Abstract:

    The Rusting evolution of MnCuP weathering steel in a simulated industrial atmosphere as a function of corrosion duration was investigated by corrosion weight gain, scanning electron microscopy, X-ray diffraction, and electrochemical methods. The results indicate that the corrosion kinetics is related closely to the Rust composition and electrochemical properties. The corrosion rate is higher during the first corrosion stage, and it is lower during the second corrosion stage. During the first corrosion stage, the Rust Layer is in low density, discontinuous, and loose, with a lower relative abundance of α-FeOOH. During the second corrosion stage, a compact and protective inner Rust Layer forms with a higher relative abundance of α-FeOOH, contributing to enhanced Rust Layer resistance. The Rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited by the protective Rust Layer. Electrochemical impedance spectroscopy tests indicate that it is more scientific to evaluate the Rust Layer protective ability by charge transfer resistance.

  • evolution of corrosion of mncup weathering steel submitted to wet dry cyclic tests in a simulated coastal atmosphere
    Corrosion Science, 2012
    Co-Authors: Long Hao, Sixun Zhang, Junhua Dong
    Abstract:

    The evolution of Rust on MnCuP weathering steel submitted to a simulated coastal atmosphere was investigated by corrosion weight gain, scanning electron microscopy. X-ray diffraction, and electrochemical methods. The results indicate that the higher corrosion rate during the first stage than that during the second stage is related closely to the Rust composition and electrochemical properties. The corrosion rate evolution is caused by the formation of a protective Rust Layer with a higher relative amount of alpha-FeOOH. The Rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited by the protective Rust Layer. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.

  • Evolution of atmospheric corrosion of MnCuP weathering steel in a simulated coastal-industrial atmosphere
    Corrosion Science, 2012
    Co-Authors: Long Hao, Sixun Zhang, Junhua Dong
    Abstract:

    Abstract The evolution of atmospheric corrosion of MnCuP weathering steel in a simulated coastal-industrial atmosphere was investigated by weight gain, SEM, XRD, and electrochemical measurements. The results indicate that the corrosion kinetics divides into two stages with a higher corrosion rate in the first stage and a lower rate in the second stage. The increased amount of α-FeOOH indicates an improved resistance of the Rust. The Rust enhances initially and then stabilizes the cathodic process, but the anodic process tends to be inhibited. The EIS results indicate that the protective ability of the Rust Layer can be evaluated by the charge transfer resistance.

Masato Yamashita - One of the best experts on this subject based on the ideXlab platform.

  • modification of Rust Layer on carbon steel with reactive actions of metallic cations for improved corrosion protectiveness
    Corrosion, 2020
    Co-Authors: Kyungtae Kim, Masato Yamashita, Hiroaki Tsuchiya, Koushu Hanaki, Shinji Fujimoto
    Abstract:

    In the present work, the modification of a Rust Layer on a carbon steel surface was examined during a cyclic corrosion test. The Rust Layer grown in a coastal region of Japan was used as a model ru...

  • taxonomy for protective ability of Rust Layer using its composition formed on weathering steel bridge
    Corrosion Science, 2007
    Co-Authors: Shuichi Hara, Takayuki Kamimura, Hideaki Miyuki, Masato Yamashita
    Abstract:

    Abstract For a quantitative evaluation of the protectiveness of a Rust Layer formed on a weathering steel bridge, the relationship between the corrosion rate of the bridge and the composition of the Rust Layers formed on the girders was first investigated. These corrosion rates were clearly classified by the protective ability index (PAI) of α / γ ∗ and ( β  +  s )/ γ ∗ , where α , γ ∗ , β and s are the mass ratio of crystalline α-FeOOH, the total of γ-FeOOH, β-FeOOH and the spinel-type iron oxide (mainly Fe 3 O 4 ), β-FeOOH and spinel-type iron oxide, analyzed by XRD, respectively. The inequality of the former index α / γ ∗  > 1 expressed the protectiveness criterion of the Rust Layer, while that of the latter index, ( β  +  s )/ γ ∗ 0.5, classified the corrosion rate of the non-protective Rust Layer. The PAI is useful for a quantitative evaluation of the protectiveness of a Rust Layer formed on a weathering steel bridge and is an important item for the corrosion assessment of the bridge.

  • x ray diffraction analysis of Rust Layer on a weathering steel bridge with surface treatment using synchrotron radiation
    Materials Transactions, 2007
    Co-Authors: Masato Yamashita, Takayuki Kamimura, Shuichi Hara, Hideaki Miyuki, Masugu Sato
    Abstract:

    We have examined the structure of Rust Layer formed on a weathering steel bridge, to which the surface treatment, employing the effect of Cr2(SO4)3 sophisticatedly designed to form the protective goethite (� -FeOOH) Rust Layer which contains a certain amount of Cr, Cr-goethite, was applied in 1996, using X-ray diffraction at SPring-8 synchrotron radiation facility. It was shown that the formation of � -FeOOH was promoted and/or crystal growth of � -FeOOH was suppressed by the surface treatment. The increase in the protective ability index (PAI) of the Rust Layer indicates that the protective goethite was predominantly formed under the effect of the surface treatment. In conclusion, it can be said that the surface treatment worked well to promote the formation of the protective goethite Rust Layer on the weathering steel bridge during the 10year exposure. [doi:10.2320/matertrans.48.579]

  • composition and protective ability of Rust Layer formed on weathering steel exposed to various environments
    Corrosion Science, 2006
    Co-Authors: Takayuki Kamimura, Masato Yamashita, Shuichi Hara, Hideaki Miyuki, Hitoshi Uchida
    Abstract:

    Abstract The compositional change of Rust (corrosion products) Layer formed on weathering steel exposed to atmosphere with different amount of air-borne sea salt particles in Japan have been investigated by the X-ray diffraction method. The mass ratio (α/γ) of crystalline α-FeOOH to γ-FeOOH, in the Rust Layer formed on the weathering steel exposed in an industrial environment, increases with an increase in exposure duration. The α/γ is closely related to the corrosion rate in environments when the amount of air-borne salt is less than 0.2 mg NaCl/dm 2 /day (2.31 × 10 −7  g NaCl/m 2 /s). However this is not the case in seaside environments with a higher amount of air-borne salts. The mass ratio (α/γ ∗ ) of crystalline α-FeOOH to the total mass of γ-FeOOH, β-FeOOH and Fe 3 O 4 , in the Rust Layer formed on the weathering steel is related to the corrosion rate even in seaside environments certainly more than 0.2 mg/dm 2 /day (2.31 × 10 −7  g/m 2 /s) of air-borne salt particles. When the α/γ ∗ is more than 1, a higher corrosion rate more than 0.01 mm/year (3.17 × 10 −13  m/s) is not observed. The α/γ ∗ is a protective ability index of Rust formed on weathering steel.

  • in situ observation of initial Rust formation process on carbon steel under na2so4 and nacl solution films with wet dry cycles using synchrotron radiation x rays
    Corrosion Science, 2005
    Co-Authors: Masato Yamashita, H. Konishi, Junichiro Mizuki, T Kozakura, Hitoshi Uchida
    Abstract:

    Abstract Atmospheric corrosion of steel proceeds under thin electrolyte film formed by rain and dew condensation followed by wet and dry cycles. It is said that Rust Layer formed on steel as a result of atmospheric corrosion strongly affects the corrosion behavior of steel. The effect of environmental corrosiveness on the formation process and structure of the Rust Layer is, however, not clear to date. In this study, in situ observation of the Rusting process of a carbon steel covered with a thin film of Na 2 SO 4 or NaCl solution was performed under a wet/dry repeating condition by X-ray diffraction spectroscopy with white X-rays obtained from synchrotron radiation. The present in situ experiments successfully detected initial process of the Rust formation. In the early cycles, the Rust constituents were not well crystallized yet, but the presence of Fe(OH) 2 and Fe(OH) 3 was confirmed. In the subsequent cycles, two different solutions resulted in difference in preferential phase of the Rust constituents. α-FeOOH was preferentially formed in the case of the Na 2 SO 4 solution film, whereas β-FeOOH appeared only under the NaCl solution film.

Xiaogang Li - One of the best experts on this subject based on the ideXlab platform.

  • effects of the addition of cu and ni on the corrosion behavior of weathering steels in corrosive industrial environments
    Journal of Materials Engineering and Performance, 2020
    Co-Authors: Tianyi Zhang, Baojun Dong, Yonggang Zhao, Junsheng Wu, Zhan Zhang, Xiaogang Li
    Abstract:

    The effect of Cu and Ni content on the corrosion behaviors of weathering steels in a corrosive atmosphere was investigated using electrochemical measurement techniques, such as electrochemical impedance spectroscopy and linear polarization resistance methods. Scanning electron microscopy with energy-dispersive spectrometry (EDS) and x-ray diffraction (XRD) were used to analyze the samples. The corrosion rates, which are above 2.0 mm a−1 at 48 h and approximately 1.12 mm a−1 at the range of 144-240 h, show that Cu and Ni slowed down the electrochemical reaction at the initial corrosion stage. With an increasing immersion time, the protective properties of the Rust Layer exhibited an increase in its impedance, and it was enhanced compared to that in the initial stage. The enrichment phenomenon of Cu and Ni elements in the inner Rust Layer was more evident in the 0.4Cu-0.4Ni and 0.7Cu-0.7Ni steels than that of 0.3Cu-0.3Ni steel after 240 h. The XRD and EDS results show that the inner Rust Layer contained compositions of CuO and Ni compounds, which filled up the pores located on the corrosion products contributing to the densification of the Rust Layer.

  • electrochemical characterization and stress corrosion cracking of e690 high strength steel in wet dry cyclic marine environments
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018
    Co-Authors: Wei Wu, Xiaogang Li, Cuiwei Du, Dawei Zhang
    Abstract:

    Abstract In this work, stress corrosion cracking (SCC) in E690 high-strength steel was investigated in simulated wet-dry cyclic marine environments using electrochemical techniques, constant load SCC examinations, morphology characterization via scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). It was found that E690 steel exhibited high SCC susceptibility in wet-dry cyclic offshore environments. The SCC follows a combined mechanism of anodic dissolution and hydrogen embrittlement, which nucleate in pits beneath the Rust Layer and tend to propagate along bainite slices in a transgranular fashion. Cracks grow with a low propagation rate during the early stage and expand with a far faster rate when the crack size exceeds a critical value. Both the electrochemical and SCC behavior of the E690 steel in wet-dry cyclic environments were influenced by the Rust Layer. The Rust scale causes enrichment of chloride in the subLayer and localized acidification. This synergistic effect is responsible for the mechanism and properties of SCC in this material.

  • atmospheric corrosion behavior and mechanism of a ni advanced weathering steel in simulated tropical marine environment
    Journal of Materials Engineering and Performance, 2017
    Co-Authors: Wei Wu, Xuequn Cheng, Zhongping Zeng, Xiaogang Li
    Abstract:

    Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner Rust Layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl−, was effectively separated in the outer Rust Layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

Hitoshi Uchida - One of the best experts on this subject based on the ideXlab platform.

  • composition and protective ability of Rust Layer formed on weathering steel exposed to various environments
    Corrosion Science, 2006
    Co-Authors: Takayuki Kamimura, Masato Yamashita, Shuichi Hara, Hideaki Miyuki, Hitoshi Uchida
    Abstract:

    Abstract The compositional change of Rust (corrosion products) Layer formed on weathering steel exposed to atmosphere with different amount of air-borne sea salt particles in Japan have been investigated by the X-ray diffraction method. The mass ratio (α/γ) of crystalline α-FeOOH to γ-FeOOH, in the Rust Layer formed on the weathering steel exposed in an industrial environment, increases with an increase in exposure duration. The α/γ is closely related to the corrosion rate in environments when the amount of air-borne salt is less than 0.2 mg NaCl/dm 2 /day (2.31 × 10 −7  g NaCl/m 2 /s). However this is not the case in seaside environments with a higher amount of air-borne salts. The mass ratio (α/γ ∗ ) of crystalline α-FeOOH to the total mass of γ-FeOOH, β-FeOOH and Fe 3 O 4 , in the Rust Layer formed on the weathering steel is related to the corrosion rate even in seaside environments certainly more than 0.2 mg/dm 2 /day (2.31 × 10 −7  g/m 2 /s) of air-borne salt particles. When the α/γ ∗ is more than 1, a higher corrosion rate more than 0.01 mm/year (3.17 × 10 −13  m/s) is not observed. The α/γ ∗ is a protective ability index of Rust formed on weathering steel.

  • in situ observation of initial Rust formation process on carbon steel under na2so4 and nacl solution films with wet dry cycles using synchrotron radiation x rays
    Corrosion Science, 2005
    Co-Authors: Masato Yamashita, H. Konishi, Junichiro Mizuki, T Kozakura, Hitoshi Uchida
    Abstract:

    Abstract Atmospheric corrosion of steel proceeds under thin electrolyte film formed by rain and dew condensation followed by wet and dry cycles. It is said that Rust Layer formed on steel as a result of atmospheric corrosion strongly affects the corrosion behavior of steel. The effect of environmental corrosiveness on the formation process and structure of the Rust Layer is, however, not clear to date. In this study, in situ observation of the Rusting process of a carbon steel covered with a thin film of Na 2 SO 4 or NaCl solution was performed under a wet/dry repeating condition by X-ray diffraction spectroscopy with white X-rays obtained from synchrotron radiation. The present in situ experiments successfully detected initial process of the Rust formation. In the early cycles, the Rust constituents were not well crystallized yet, but the presence of Fe(OH) 2 and Fe(OH) 3 was confirmed. In the subsequent cycles, two different solutions resulted in difference in preferential phase of the Rust constituents. α-FeOOH was preferentially formed in the case of the Na 2 SO 4 solution film, whereas β-FeOOH appeared only under the NaCl solution film.

  • characterization of Rust Layer formed on fe fe ni and fe cr alloys exposed to cl rich environment by cl and fe k edge xanes measurements
    Materials Transactions, 2005
    Co-Authors: H. Konishi, Masato Yamashita, Hitoshi Uchida, Junichiro Mizuki
    Abstract:

    Chloride in atmosphere considerably reduces the corrosion resistance of conventional weathering steel containing a small amount of Cr. Ni is an effective anticon-osive element for improving the corrosion resistance of steel in a Cl-rich environment. In order to clarify the structure of the protective Rust Layer of weathering steel, Cl and Fe K-edge X-ray absorption near edge structure (XANES) spectra of atmospheric corrosion products (Rust) formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich atmosphere were measured. The Fe K-XANES measurements enable the characterization of a mixture of iron oxides such as Rust. The chemical composition of the Rust was determined by performing pattern fitting of the measured spectra. All the Rust is composed mainly of goethite, akaganeite, lepidocrocite and magnetite. Among these iron oxides, akaganeite in particular is the major component in the Rust. Additionally, the amount of akaganeite in the Rust of Fe-Ni alloy is much greater than that in Rust of Fe-Cr alloy. Akaganeite is generally considered to facilitate the corrosion of steel, but our results indicate that akaganeite in the Rust of Fe-Ni alloy is quantitatively different from that in Rust of Fe-Cr alloy and does not facilitate the corrosion of steel. The shoulder peak observed in Cl K-XANES spectra reveals that the Rust contains a chloride other than akaganeite. The energy of the shoulder peak does not correspond to that of any well-known chlorides. In the measured spectra, there is no proof that Cl, by combining with the alloying element, inhibits the alloying element from acting in corrosion resistance. The shoulder peak appears only when the content of the alloying element is lower than a certain value. This suggests that the generation of the unidentified chloride is related to the corrosion rate of steel.

  • nanostructure of protective Rust Layer on weathering steel examined using synchrotron radiation x rays
    Materials Transactions, 2004
    Co-Authors: Masato Yamashita, H. Konishi, Junichiro Mizuki, Hitoshi Uchida
    Abstract:

    The X-ray absorption fine structure (XAFS) spectrum of pure goethite around the Fe K absorption edge and that of the protective Rust Layer formed on weathering steel exposed for 17 years in an atmospheric environment around the Cr K edge, have been examined using synchrotron radiation X-rays. It was found that the Rust Layer on the weathering steel mainly consisted of Cr-goethite. By examining the fine structure at the Cr K edge and the Fe K edge, we concluded that Cr 3þ in the Rust Layer is coordinated with O 2� and is positioned in the double chains of vacant sites in the network of FeO3(OH)3 octahedra in the goethite crystal. This Cr 3þ site indicates that the protective effect of the Rust Layer is due to the dense aggregation of fine crystals of Cr-goethite with cation selectivity.

  • structure and protective performance of atmospheric corrosion product of fe cr alloy film analyzed by mossbauer spectroscopy and with synchrotron radiation x rays
    Corrosion Science, 2003
    Co-Authors: Masato Yamashita, H. Konishi, Hitoshi Uchida
    Abstract:

    Abstract The structure of atmospheric corrosion product of Fe–5 mass%Cr alloy film has been examined by using synchrotron radiation X-rays and γ-rays for Mossbauer spectroscopy. The relationship between the position of Cr 3+ in the atomic arrangement of the Rust crystal and the protective performance of the Rust Layer is discussed. It was found that the Rust Layer of the Fe–Cr alloy film contains a large amount of ultrafine Cr–goethite. By analyzing the X-ray absorption fine structure at Cr K-edge of the Rust Layer, we can conclude that Cr 3+ is positioned in the double chains of vacant sites in the network of FeO 3 (OH) 3 octahedra in the goethite crystal. This Cr 3+ site might explain the protective performance, owing to dense aggregation of fine crystals with cation selectivity, of the Cr–goethite.

Tianyi Zhang - One of the best experts on this subject based on the ideXlab platform.

  • optimizing the resistance of ni advanced weathering steel to marine atmospheric corrosion with the addition of al or mo
    Construction and Building Materials, 2021
    Co-Authors: Tianyi Zhang, Shan Jiang, Jianwei Yang, Zhiyong Liu
    Abstract:

    Abstract Self-designed Ni-advanced weathering steels alloyed with Al and Mo tested in simulated tropical marine atmospheric environment was investigated through microstructure characterization, Rust analysis, and electrochemical methods. The results showed that the addition of Al and Mo in 1Ni steel (Ni content: 1 wt%) is beneficial to improve the corrosion resistance in longer time periods, and thicker protective Rust Layer can be formed on the steel surface when Mo is added than when Al is added. XPS analysis on the Rust indicates that MoO2 and MoO3 can prevent the degradation of NiFe2O4, thereby maintaining an electronegative inner Layer in the Rust to resist Cl−. The large-sized Al-enriched particles, which consist of AlOOH and Al(OH)3, are unable to block the invasion of Cl−, but the corrosion products with the same phase can fill in the pores and cracks, which makes the Rust Layer compact and increases the resistance of the Rust Layer.

  • effects of the addition of cu and ni on the corrosion behavior of weathering steels in corrosive industrial environments
    Journal of Materials Engineering and Performance, 2020
    Co-Authors: Tianyi Zhang, Baojun Dong, Yonggang Zhao, Junsheng Wu, Zhan Zhang, Xiaogang Li
    Abstract:

    The effect of Cu and Ni content on the corrosion behaviors of weathering steels in a corrosive atmosphere was investigated using electrochemical measurement techniques, such as electrochemical impedance spectroscopy and linear polarization resistance methods. Scanning electron microscopy with energy-dispersive spectrometry (EDS) and x-ray diffraction (XRD) were used to analyze the samples. The corrosion rates, which are above 2.0 mm a−1 at 48 h and approximately 1.12 mm a−1 at the range of 144-240 h, show that Cu and Ni slowed down the electrochemical reaction at the initial corrosion stage. With an increasing immersion time, the protective properties of the Rust Layer exhibited an increase in its impedance, and it was enhanced compared to that in the initial stage. The enrichment phenomenon of Cu and Ni elements in the inner Rust Layer was more evident in the 0.4Cu-0.4Ni and 0.7Cu-0.7Ni steels than that of 0.3Cu-0.3Ni steel after 240 h. The XRD and EDS results show that the inner Rust Layer contained compositions of CuO and Ni compounds, which filled up the pores located on the corrosion products contributing to the densification of the Rust Layer.

  • evolution of Rust Layers on carbon steel and weathering steel in high humidity and heat marine atmospheric corrosion
    Journal of Materials Science & Technology, 2020
    Co-Authors: Yueming Fan, Baojun Dong, Yonggang Zhao, Wei Liu, Thee Chowwanonthapunya, Banthukul Wongpat, Tianyi Zhang
    Abstract:

    Abstract The evolution of the Rust Layers on carbon steel and weathering steel in high humidity and heat marine atmospheric environment was investigated by wet/dry cyclic acceleration corrosion tests in this study. The corrosion process of carbon steel and weathering steel was divided into two stages and the reasons for the changes in the corrosion rates of two steels were different. The composition phase of the inner Rust Layer of weathering steel was mainly goethite, whereas that of carbon steel was mainly akaganeite. Rust resistance (Rr) performed better than charge transfer resistance (Rt) in evaluating the protection performance of Rust Layer. As the corrosion proceeded, the evolution of the cathodic process of weathering steel was not obvious, whereas that of carbon steel was irregular.