Effects of niobium and rare earth elements on microstructure and initial marine corrosion behavior of low-alloy steels

Zhang, Xian; Wei, Wenzhui; Cheng, Lin; Liu, Jing; Wu, Kaiming; Liu, Min

doi:10.1016/j.apsusc.2018.12.243

Cited by 69 publications

(37 citation statements)

References 51 publications

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“…However, with the increase of the volume fraction of ceramic particles, the impact toughness of the composite coating decreases seriously, resulting in particle breakage or matrix cracking in some environments, and the corrosion resistance decreases instead. Therefore, improving the impact toughness of composite coating without losing their corrosion resistance has become the research focus of particle reinforced metal-based materials [19,20].…”

Section: Introductionmentioning

confidence: 99%

Effect of CeO2 on Impact Toughness and Corrosion Resistance of WC Reinforced Al-Based Coating by Laser Cladding

2019

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WC reinforced Al-based coating with added CeO2 was prepared on the surface of S420 steel by laser cladding. The microstructure and structure of the coatings were analyzed by scanning electron microscope, X-ray diffractometer and optical profiler. The mechanical properties and corrosion properties of the coatings were studied by microhardness tester, friction and wear tester, Charpy impact tester, and electrochemical workstation. The results show that the coating is mainly composed of Al-phase, continuous-phase, and hard reinforced-phase WC, and the coating and substrate show good metallurgical bonding. When the content of CeO2 is 1%, the fine grain strengthening effect is obvious, and the impact toughness of the coating is obviously improved. Appropriate amount of rare earth CeO2 can significantly improve the hardness of the coating. When the content of CeO2 is more than 1%, the wear resistance of the coating decreases. The coating prepared with different CeO2 content has higher impedance and corrosion resistance than that of the substrate. At 1% CeO2 content, the coating has the best corrosion resistance.

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Section: Introductionmentioning

confidence: 99%

Effect of CeO2 on Impact Toughness and Corrosion Resistance of WC Reinforced Al-Based Coating by Laser Cladding

2019

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“…During the experiments, the potential differences between the vibration peak and valley, Δ E , were detected by an electrometer incorporated in this equipment. Therefore, the local distribution of current density could be acquired through the equation I = −Δ E / R , where R represents the solution resistance and equals the ratio of d / k ( k is the solution conductivity, 8.42 mS/cm for a 0.5% NaCl solution) [1,41]. The Δ E values of a region of 400 × 400 μm were recorded at the beginning of corrosion and after corrosion for 1 h, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…However, these studies provided only superficial descriptions and lacked in-depth analyses. Relatively few researches have elaborately studied the effects of RE-doped inclusions on the corrosion behavior of steels [35,36,37,41].…”

Section: Introductionmentioning

confidence: 99%

Mechanism Understanding of the Role of Rare Earth Inclusions in the Initial Marine Corrosion Process of Microalloyed Steels

Tang

Liu

et al. 2019

Materials

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In this study, the corrosion behavior of rare earth (RE) microalloyed steels was first evaluated through potentiodynamic polarization tests and corrosion weight loss experiments, and then the corrosion morphologies were observed by scanning electron microscope (SEM). After immersion in a NaCl solution, the sulfides (or oxygen sulfides) dissolved preferentially, followed by corrosion at the boundary between the Fe matrix and oxides. Afterwards, the inclusions fell off as a whole, which promoted pitting nucleation. The first principle modeling demonstrated that the work functions of various kinds of inclusions descended in the following order: La2Zr2O7 > LaAlO3 > (La2O3 ≈ Fe ≈ La2O2S) > La2S3, which provided a theoretical explanation to the dissolution behaviors of inclusions. That is, inclusions containing sulfur tend to dissolve preferentially, whereas the oxides do not dissolve easily. Subsequently, the surface current distributions were detected by the scanning vibrating electrode technique (SVET), which provided more microscopic insight into the role of inclusions in the corrosion propagation. Results showed that the active sites of pitting nucleation accelerated the transverse propagation of corrosion. Finally, local corrosion spread to the whole surface as uniform corrosion.

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“…The addition of RE elements into steels can modify the inclusions to form spherical RE-sulfides and (RE, Al)-oxy-sulfides with a smaller size, as shown in the Figure 11. In traditional steels, non-metallic inclusions especially MnS often provide initiation sites for pitting corrosion [21]. Because MnS often acts as a cathode and the matrix acts as an anode in a corrosion system, the oxide film between MnS and the substrate is easily destroyed by aggressive ions.…”

Section: Figurementioning

confidence: 99%

“…In addition, RE element is active and probably enriched at the interfaces such as grain boundaries or surfaces due to the big difference of atomic radius between RE and iron [17][18][19]. The microstructure and corrosion properties are changed because of the concentration of RE elements at grain boundaries, which affects the diffusion of other elements and restrain the nucleation and growth of new phases [20,21]. RE also segregates towards interfaces, which is considered as the micro-alloying effect, though it differs from what is commonly thought as solid solution effect.…”

Section: Introductionmentioning

confidence: 99%

Effects of Rare Earth (Ce and La) on Steel Corrosion Behaviors under Wet-Dry Cycle Immersion Conditions

Lian

Zhu

Wang

et al. 2020

Metals

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Rare earth (RE) elements are beneficial to improving corrosion properties in low-carbon and low-alloy steels. In this paper, corrosion performance of Q235B steel and Q355B steel samples after RE alloying under wet-dry cycle immersion conditions were analyzed. Experimental results show that corrosion rate was significantly decreased. It was probably due to the grain refinement by RE alloying, which increased the density of protective rust layers and improved corrosion resistance. The formation of small-sized spherical RE inclusions also inhibited the precipitation of MnS and weakened micro galvanic corrosion. Additionally, RE atoms tended to segregate towards grain boundaries and a RE concentration region is formed between rust layers and matrix to impede the access from contacting corrosive ions. A corrosion resistance schematic of RE atom segregation was proposed based on microstructure morphology and element distribution results.

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Effects of niobium and rare earth elements on microstructure and initial marine corrosion behavior of low-alloy steels

Cited by 69 publications

References 51 publications

Effect of CeO2 on Impact Toughness and Corrosion Resistance of WC Reinforced Al-Based Coating by Laser Cladding

Effect of CeO2 on Impact Toughness and Corrosion Resistance of WC Reinforced Al-Based Coating by Laser Cladding

Mechanism Understanding of the Role of Rare Earth Inclusions in the Initial Marine Corrosion Process of Microalloyed Steels

Effects of Rare Earth (Ce and La) on Steel Corrosion Behaviors under Wet-Dry Cycle Immersion Conditions

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