A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Effect of rare earth metals on passivation behavior of UNS S31803 duplex stainless steel in sulfuric acid solution
Abstract UNS S31803 duplex stainless steel (DSS) has excellent corrosion resistance and has been widely used in sulfuric acid containing media, such as flue gas desulfurization and sulfuric acid production. However, if DSS is soaked in sulfuric acid medium for too long, partial corrosion may still occur. Rare earth (RE) can improve the corrosion resistance of stainless steel, but there is limited research on DSS containing RE in sulfuric acid medium. In this paper, the effect of RE on the corrosion and passivation behavior of UNS S31803 DSS in H2SO4 solution was investigated by using of anodic polarization, electrochemical impedance spectroscopy, scanning electron microscopy, as well as electron probe microanalysis. The results indicate that UNS S31803 DSS's corrosion resistance was improved by adding of RE, which also extended the passive range and reduced the passive current density. In 0.5 mol / L and 2 mol / L H2SO4 solutions, the passive range of steel with RE increased by 28.57% and 40.85%, compared to steel without RE. Desulfurization and purification of molten steel occurred because of adding RE, reducing the S content from 0.005% to 0.003%. RE enriching at grain boundaries can reduce segregation of S and P at grain boundaries, and make the distribution of Cr, Ni, and Mo more uniform at grain boundaries. According to Mott-Schottky curves test, after adding RE, the donor density (N D) and acceptor density (N A) were reduced from 18.44 × 1021 cm−3 and 16.74 × 1021 cm−3 to 12.73 × 1021 cm−3 and 12.65 × 1021 cm−3 in 2 mol / L H2SO4 solution, indicating that the defects of the passive film was decreased and the protective performance of film was improved.
Highlights The aggregation of rare earth at grain boundary and effect on corrosion resistance. Rare earth can desulfurize and purify molten steel. Rare earth increase the passive range and decrease the passive current density. Rare earth can increase the atomic ratio of Cr/Fe of the passivation film. Rare earth makes the passivation film thicker and denser.
Effect of rare earth metals on passivation behavior of UNS S31803 duplex stainless steel in sulfuric acid solution
Abstract UNS S31803 duplex stainless steel (DSS) has excellent corrosion resistance and has been widely used in sulfuric acid containing media, such as flue gas desulfurization and sulfuric acid production. However, if DSS is soaked in sulfuric acid medium for too long, partial corrosion may still occur. Rare earth (RE) can improve the corrosion resistance of stainless steel, but there is limited research on DSS containing RE in sulfuric acid medium. In this paper, the effect of RE on the corrosion and passivation behavior of UNS S31803 DSS in H2SO4 solution was investigated by using of anodic polarization, electrochemical impedance spectroscopy, scanning electron microscopy, as well as electron probe microanalysis. The results indicate that UNS S31803 DSS's corrosion resistance was improved by adding of RE, which also extended the passive range and reduced the passive current density. In 0.5 mol / L and 2 mol / L H2SO4 solutions, the passive range of steel with RE increased by 28.57% and 40.85%, compared to steel without RE. Desulfurization and purification of molten steel occurred because of adding RE, reducing the S content from 0.005% to 0.003%. RE enriching at grain boundaries can reduce segregation of S and P at grain boundaries, and make the distribution of Cr, Ni, and Mo more uniform at grain boundaries. According to Mott-Schottky curves test, after adding RE, the donor density (N D) and acceptor density (N A) were reduced from 18.44 × 1021 cm−3 and 16.74 × 1021 cm−3 to 12.73 × 1021 cm−3 and 12.65 × 1021 cm−3 in 2 mol / L H2SO4 solution, indicating that the defects of the passive film was decreased and the protective performance of film was improved.
Highlights The aggregation of rare earth at grain boundary and effect on corrosion resistance. Rare earth can desulfurize and purify molten steel. Rare earth increase the passive range and decrease the passive current density. Rare earth can increase the atomic ratio of Cr/Fe of the passivation film. Rare earth makes the passivation film thicker and denser.
Effect of rare earth metals on passivation behavior of UNS S31803 duplex stainless steel in sulfuric acid solution
Liu, Xiao (author) / Ju, Dianchun (author) / Chen, Lei (author)
2024-02-27
Article (Journal)
Electronic Resource
English
Passivation Behavior of Ce-Containing Hyper Duplex Stainless Steels in Sulfuric Acid Solution
| British Library Online Contents | 2015
Environmental Effects on the Fracture Toughness of a Duplex Stainless Steel (UNS S31803)
| British Library Online Contents | 2007
| British Library Online Contents | 2007