The effect of nanosized NbC precipitates on electrochemical corrosion behavior of high-strength low-alloy steel in 3.5%NaCl solution

Fan

et al. 2021

steel research int.

Self Cite

Microstructure observations, thermal desorption spectroscopy (TDS) tests, hydrogen permeation measurements, electrochemical tests, and slow strain rate tensile (SSRT) tests are conducted investigate the beneficial effect of Nb microalloying on the stress corrosion cracking (SCC) behavior of high-strength low-alloy (HSLA) steels in a simulated deep-sea environment. The results show that the addition of Nb significantly decreases the SCC susceptibility of HSLA steel in a simulated deep-sea environment, and the role of Nb is attributed to microstructure optimization and the strong hydrogen-trap function of nanosized NbC precipitates with hydrogen activation energy up to 100.5 kJ mol À1 . In the simulated deep-sea environment, the SCC resistance of HSLA steel is enhanced by microstructure optimization and the hydrogen-trap function via Nb microalloying, and both anodic dissolution (AD) and hydrogen embrittlement (HE) are weakened. Moreover, the improvement of SCC resistance of HSLA steel with a higher hydrogen concentration via Nb microalloying is more obvious, in which the decrease of hydrogen-induced anodic dissolution (HIAD) and HE effects is more distinct, and the strong hydrogen-trap effect of NbC precipitates is the predominant mechanism to improve SCC resistance.

Section: Introductionmentioning

confidence: 85%

Improved Stress Corrosion Cracking Resistance of High‐Strength Low‐Alloy Steel in a Simulated Deep‐Sea Environment via Nb Microalloying

Fan

et al. 2021

steel research int.

Self Cite

J. Iron Steel Res. Int.

“…Finally, specimens were cooled in air to room temperature from 230 °C. [20]. The specimens were mechanically polished to 2000-grit SiC emery paper on both sides.…”

Section: Methodsmentioning

confidence: 99%

“…The aqueous solution in the hydrogen detection cell was 0.2 mol/L NaOH and in the hydrogen charging cell was 0.25 g/L CH 4 N 4 S and 0.5 mol/L H 2 SO 4 mixed solution, in which the hydrogen charging current density was 1.0 mA/cm 2 . A device schematic of the Devanathane-Stachurski setup is shown in Fig. 2a [20][21][22], and specimen dimension is shown in Fig. 2b.…”

Section: Methodsmentioning

confidence: 99%

Effect of vanadium on hydrogen embrittlement susceptibility of high-strength hot-stamped steel

Chen

Gao

Wang

et al. 2020

Based on the chemical composition of traditional hot-stamped steel (e.g., 22MnB5 and 30MnB5), Nb and V microalloying elements are added into 30MnB5 steel to meet the requirements of ultra-high strength, excellent ductility and potent resistance to hydrogen embrittlement (HE) at the same time. The influence of hot-stamped steel on HE was studied by conducting a hydrogen permeation method and pre-charged hydrogen slow strain rate test. Meanwhile, the experimental steel microstructures and corresponding fracture surfaces are observed and analyzed to characterize HE behavior. The results show that a finer microstructure, a lower apparent diffusion coefficient of hydrogen and a smaller percentage of strength and plasticity reduction are obtained due to the addition of the vanadium element into hot-stamped steel. Compared to the V free experimental steel, the steel with 0.14 wt.% V has a large number of dispersive precipitates and more grain boundary areas, which makes hydrogen atoms dispersedly distribute.

“…In the SG + CaCl 2 solution (Figure 1a), the curves are very similar, characterized as active dissolution control in both the anodic and cathodic areas. The anodic polarization curves appear in the active dissolution region, but are without occurrence in the passivation region [26,27]. Both the SG and CaCl 2 solutions contain active Cl − , which easily destroys the protective oxide film formed on the iron surface and triggers the dissolution of the iron, further accelerating the electrochemical corrosion activity.…”

Section: Potentiodynamic Polarization Curvesmentioning

confidence: 99%

Effects of Different Ions and Temperature on Corrosion Behavior of Pure Iron in Anoxic Simulated Groundwater

Huang

Feng

et al. 2020

Materials

As a typical material of the insert in high-level radioactive waste (HLW) geological disposal canisters, iron-based materials will directly contact with groundwater after the failure of a metallic canister, acting as a chemical barrier to prevent HLW leaking into groundwater. In this paper, anoxic groundwater was simulated by mixing 10 mM NaCl and 2 mM NaHCO3 purged by Ar gas (containing 0.3% CO2) with different added ions (Ca2+, CO32− and SiO32−) and operation temperatures (25, 40 and 60 °C). An electrochemical measurement, immersion tests and surface characterization were carried out to study the corrosion behavior of pure iron in the simulated groundwater. The effects of Ca2+ on the corrosion behavior of iron is negligible, however, Cl− plays an important role in accelerating the corrosion activity with the increased concentration and temperature. With increased concentrations of CO32− and SiO32−, the corrosion resistance of iron is largely improved, which is attributed to the formation of a uniform passivation film. The independent effects of temperature on the corrosion behavior of iron are resulted from the repeated passivation–dissolution processes in the formation of the passivation film, resulting from the synergistic effects of CO32−/SiO32− and Cl−. The formation of ferric silicate is dominant in the passivation film with the addition of SiO32−, which effectively protects the iron surface from corrosion.