Pub Date : 2026-10-16DOI: 10.1016/j.corsci.2026.114351
Hao-Jie Yan, Hong-Ji Wan, Xin-Yu Ye, Jun-Xi Chen, Hao Li, Hui-Song Hu, Xin-Ran Li, Tao Fan, Hui-Jun Liu, Lian-Kui Wu, Fa-He Cao
To mitigate detrimental interdiffusion at the TiAl/CrAlN interface, a compact α-Al2O3 diffusion barrier was developed on TiAl alloy via anodic fluorination and pre-oxidation. After 100 h of oxidation at 900 °C, the resulting α-Al2O3/CrAlN composite coating exhibits a mass gain of just 0.44± 0.03 mg cm-2, only 55% of that of the CrAlN coating, underscoring its markedly superior oxidation resistance. The CrAlN top-coating serves as the primary oxidation barrier by forming a continuous (Al,Cr)2O3 scale. Meanwhile, the in-situ generated α-Al2O3 barrier establishes a semi-coherent interface with the Ti3Al layer, ensuring excellent interfacial adhesion. More importantly, this barrier significantly suppresses bidirectional diffusion of Ti, Cr, and Al, thereby inhibiting the formation of an interdiffusion zone (IDZ) and secondary reaction zone (SRZ), which significantly extends the service life of the CrAlN coating. Furthermore, the α-Al2O3 interlayer, with its moderate thermal expansion coefficient, functions as a stress buffer to relieve interfacial thermal mismatch stresses.
{"title":"Interfacial strengthening and diffusion resistance mechanism of a fluorination-induced α-Al2O3 barrier in the TiAl/α-Al2O3/CrAlN system","authors":"Hao-Jie Yan, Hong-Ji Wan, Xin-Yu Ye, Jun-Xi Chen, Hao Li, Hui-Song Hu, Xin-Ran Li, Tao Fan, Hui-Jun Liu, Lian-Kui Wu, Fa-He Cao","doi":"10.1016/j.corsci.2026.114351","DOIUrl":"10.1016/j.corsci.2026.114351","url":null,"abstract":"<div><div>To mitigate detrimental interdiffusion at the TiAl/CrAlN interface, a compact α-Al<sub>2</sub>O<sub>3</sub> diffusion barrier was developed on TiAl alloy <em>via</em> anodic fluorination and pre-oxidation. After 100<!--> <!-->h of oxidation at 900 °C, the resulting α-Al<sub>2</sub>O<sub>3</sub>/CrAlN composite coating exhibits a mass gain of just 0.44± 0.03<!--> <!-->mg<!--> <!-->cm<sup>-2</sup>, only 55% of that of the CrAlN coating, underscoring its markedly superior oxidation resistance. The CrAlN top-coating serves as the primary oxidation barrier by forming a continuous (Al,Cr)<sub>2</sub>O<sub>3</sub> scale. Meanwhile, the in-situ generated α-Al<sub>2</sub>O<sub>3</sub> barrier establishes a semi-coherent interface with the Ti<sub>3</sub>Al layer, ensuring excellent interfacial adhesion. More importantly, this barrier significantly suppresses bidirectional diffusion of Ti, Cr, and Al, thereby inhibiting the formation of an interdiffusion zone (IDZ) and secondary reaction zone (SRZ), which significantly extends the service life of the CrAlN coating. Furthermore, the α-Al<sub>2</sub>O<sub>3</sub> interlayer, with its moderate thermal expansion coefficient, functions as a stress buffer to relieve interfacial thermal mismatch stresses.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"273 ","pages":"Article 114351"},"PeriodicalIF":10.3,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149212974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-06DOI: 10.1016/j.corsci.2026.113681
A.E. Yaedu , S. Palkó , J. Rafferty , L. Volpe , A. Shaik , K. Daub , N. Huin , F. Scenini , S.Y. Persaud
Primary water stress corrosion cracking (PWSCC) of Alloys 600 and X-750 is believed to occur via a preferential intergranular oxidation (PIO) mechanism, in which only the alloying elements are oxidized, leaving Ni metallic. Superheated H2-steam has been used as an accelerated environment for PWSCC studies, supported by comparable Arrhenius activation energies. Since the PIO model does not require an aqueous solution, this study investigates the occurrence of PIO and SCC in Alloy X-750 exposed to a 480 °C CO–CO₂ mixture. Post-experiment nanoscale characterization of fractured samples revealed characteristics consistent with PWSCC, including PIO and Ni enrichment, accompanied by cavity formation.
{"title":"Stress corrosion cracking of Alloy X-750 in a CO-CO2 reducing gas mixture","authors":"A.E. Yaedu , S. Palkó , J. Rafferty , L. Volpe , A. Shaik , K. Daub , N. Huin , F. Scenini , S.Y. Persaud","doi":"10.1016/j.corsci.2026.113681","DOIUrl":"10.1016/j.corsci.2026.113681","url":null,"abstract":"<div><div>Primary water stress corrosion cracking (PWSCC) of Alloys 600 and X-750 is believed to occur via a preferential intergranular oxidation (PIO) mechanism, in which only the alloying elements are oxidized, leaving Ni metallic. Superheated H<sub>2</sub>-steam has been used as an accelerated environment for PWSCC studies, supported by comparable Arrhenius activation energies. Since the PIO model does not require an aqueous solution, this study investigates the occurrence of PIO and SCC in Alloy X-750 exposed to a 480 °C CO–CO₂ mixture. Post-experiment nanoscale characterization of fractured samples revealed characteristics consistent with PWSCC, including PIO and Ni enrichment, accompanied by cavity formation.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113681"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-10DOI: 10.1016/j.corsci.2026.113693
Jiageng Zhuang , Junjie Yang , Ping Li , Zengbo Lu , Daniel John Blackwood , Zhentao Yu
To prepare plasma electrolytic oxidation (PEO) coatings on the Q345 steel (non-valve metal) surface, a Zn layer was introduced by electrodeposition. Different power regimes for PEO treatment were investigated to determine their influence on the microstructure, composition and corrosion performance. The results showed that the optimized combination of an initial constant current mode followed by a period of constant voltage mode benefited the regulation of the passivation-oxidation process and reduced the porosity of the PEO coatings, resulting in superior adhesion strength and enhanced corrosion resistance compared to either constant current or constant voltage modes alone. This improvement can be attributed to the preservation of the intact Zn layer and the optimization of the coating’s microstructure.
{"title":"Fabrication and corrosion behavior of plasma electrolytic oxidation (PEO) coatings on Zn-deposited carbon steel","authors":"Jiageng Zhuang , Junjie Yang , Ping Li , Zengbo Lu , Daniel John Blackwood , Zhentao Yu","doi":"10.1016/j.corsci.2026.113693","DOIUrl":"10.1016/j.corsci.2026.113693","url":null,"abstract":"<div><div>To prepare plasma electrolytic oxidation (PEO) coatings on the Q345 steel (non-valve metal) surface, a Zn layer was introduced by electrodeposition. Different power regimes for PEO treatment were investigated to determine their influence on the microstructure, composition and corrosion performance. The results showed that the optimized combination of an initial constant current mode followed by a period of constant voltage mode benefited the regulation of the passivation-oxidation process and reduced the porosity of the PEO coatings, resulting in superior adhesion strength and enhanced corrosion resistance compared to either constant current or constant voltage modes alone. This improvement can be attributed to the preservation of the intact Zn layer and the optimization of the coating’s microstructure.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113693"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-05DOI: 10.1016/j.corsci.2026.113692
Yueh-Cheng Yu, David L. Poerschke
Aluminide bond coats are widely used as oxidation-resistant layers in coating systems for gas turbines, where a protective Al2O3 thermally grown oxide (TGO) forms to mitigate oxidation of the underlying substrate. Nickel (Ni) aluminide-based bond coats work well for Ni-based superalloys, but these alloys are approaching their limits as the operating temperatures of turbine engines continue to increase. This study investigated the oxidation behavior for a series of ruthenium-palladium (Ru,Pd) aluminides ranging from pure RuAl to PdAl at 1300 °C, a target temperature for next-generation bond coat applications. The results show that the incorporation of Pd into RuAl enables the formation of a stable and uniform Al2O3 scale. At low and moderate Pd additions, Kirkendall voids form below the growing TGO; higher Pd concentrations reduce the void formation but are more likely to lead to scale spallation. The addition of hafnium (Hf) as a reactive element slows the TGO growth and pore formation, and enhances its adhesion. With careful composition refinement, (Ru,Pd)-aluminides can be promising bond coat candidates for niobium (Nb)-based alloys due to their compatible coefficient of thermal expansion and improved oxidation resistance at high temperatures.
{"title":"Oxidation behavior of RuAl, PdAl, and ruthenium-palladium aluminides for bond coat applications","authors":"Yueh-Cheng Yu, David L. Poerschke","doi":"10.1016/j.corsci.2026.113692","DOIUrl":"10.1016/j.corsci.2026.113692","url":null,"abstract":"<div><div>Aluminide bond coats are widely used as oxidation-resistant layers in coating systems for gas turbines, where a protective Al<sub>2</sub>O<sub>3</sub> thermally grown oxide (TGO) forms to mitigate oxidation of the underlying substrate. Nickel (Ni) aluminide-based bond coats work well for Ni-based superalloys, but these alloys are approaching their limits as the operating temperatures of turbine engines continue to increase. This study investigated the oxidation behavior for a series of ruthenium-palladium (Ru,Pd) aluminides ranging from pure RuAl to PdAl at 1300 °C, a target temperature for next-generation bond coat applications. The results show that the incorporation of Pd into RuAl enables the formation of a stable and uniform Al<sub>2</sub>O<sub>3</sub> scale. At low and moderate Pd additions, Kirkendall voids form below the growing TGO; higher Pd concentrations reduce the void formation but are more likely to lead to scale spallation. The addition of hafnium (Hf) as a reactive element slows the TGO growth and pore formation, and enhances its adhesion. With careful composition refinement, (Ru,Pd)-aluminides can be promising bond coat candidates for niobium (Nb)-based alloys due to their compatible coefficient of thermal expansion and improved oxidation resistance at high temperatures.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113692"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-05DOI: 10.1016/j.corsci.2026.113690
Ke Zhao, Jun Xiao, Yuanhua Shen, Hao Wang, Yuqi Zheng, Yongwang Li
This study investigates the distinct corrosion behavior of 12 wt% Cr F/M steels in LBE at 550℃, with a focus on the influence of the initial matrix microstructure. Two steels of same composition but different initial microstructures were examined, one predominantly martensitic and the other predominantly ferritic. Under high-oxygen conditions (HOC, 1.01 ×10−3 wt% to 1.84 ×10−3 wt%), both steels formed duplex oxide scales of similar total thickness. However, the predominantly ferritic steel exhibited a thinner and discontinuous IOZ. In contrast, under low-oxygen conditions (LOC, 1.82 ×10−13 wt% to 6.25 ×10−8 wt%), the predominantly ferritic steel underwent deep LBE penetration (maximum ∼40 µm after 5000 h), markedly greater than that observed in the predominantly martensitic steel (maximum ∼10 µm after 5000 h). The key mechanistic insight reveals that the high density of microstructural interfaces (e.g., martensitic lath boundaries) within the martensite provides abundant pathways for rapid elemental diffusion (e.g., O and Cr), thereby promoting the nucleation and growth of the IOZ. Furthermore, the abundant Cr-rich M23C6 carbides precipitated at these microstructural interfaces accelerate the oxidation of interfaces due to the lower oxidation free energy of Cr. The resulting oxides facilitate the rapid formation of a continuous scale composed of Fe-Cr spinel and Cr2O3. Importantly, this oxide layer acts as an effective barrier against dissolution and LBE attack under low‑oxygen conditions. This work demonstrates the detrimental effect of ferrite on the corrosion resistance of 12 wt% Cr F/M steels in LBE and underlines the importance of microstructural design to maximize martensite content for enhanced performance.
{"title":"The role of ferrite in the LBE corrosion resistance of 12 wt% Cr F/M steels at 550℃","authors":"Ke Zhao, Jun Xiao, Yuanhua Shen, Hao Wang, Yuqi Zheng, Yongwang Li","doi":"10.1016/j.corsci.2026.113690","DOIUrl":"10.1016/j.corsci.2026.113690","url":null,"abstract":"<div><div>This study investigates the distinct corrosion behavior of 12 wt% Cr F/M steels in LBE at 550℃, with a focus on the influence of the initial matrix microstructure. Two steels of same composition but different initial microstructures were examined, one predominantly martensitic and the other predominantly ferritic. Under high-oxygen conditions (HOC, 1.01 ×10<sup>−3</sup> wt% to 1.84 ×10<sup>−3</sup> wt%), both steels formed duplex oxide scales of similar total thickness. However, the predominantly ferritic steel exhibited a thinner and discontinuous IOZ. In contrast, under low-oxygen conditions (LOC, 1.82 ×10<sup>−13</sup> wt% to 6.25 ×10<sup>−8</sup> wt%), the predominantly ferritic steel underwent deep LBE penetration (maximum ∼40 µm after 5000 h), markedly greater than that observed in the predominantly martensitic steel (maximum ∼10 µm after 5000 h). The key mechanistic insight reveals that the high density of microstructural interfaces (e.g., martensitic lath boundaries) within the martensite provides abundant pathways for rapid elemental diffusion (e.g., O and Cr), thereby promoting the nucleation and growth of the IOZ. Furthermore, the abundant Cr-rich M<sub>23</sub>C<sub>6</sub> carbides precipitated at these microstructural interfaces accelerate the oxidation of interfaces due to the lower oxidation free energy of Cr. The resulting oxides facilitate the rapid formation of a continuous scale composed of Fe-Cr spinel and Cr<sub>2</sub>O<sub>3</sub>. Importantly, this oxide layer acts as an effective barrier against dissolution and LBE attack under low‑oxygen conditions. This work demonstrates the detrimental effect of ferrite on the corrosion resistance of 12 wt% Cr F/M steels in LBE and underlines the importance of microstructural design to maximize martensite content for enhanced performance.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113690"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-06DOI: 10.1016/j.corsci.2026.113667
James Rafferty , Sándor Palkó , Marc Chevalier , Robert Ainsworth , Fabio Scenini
This study demonstrates how surface preparation and mechanical loading affect oxidation and carburisation in 316 H stainless steel exposed to CO/CO₂ environments. OPS‑polished surfaces exhibited the greatest susceptibility, forming thick duplex oxides that enabled carbon ingress and substantial hardening, particularly under creep at 350 MPa. The permeability of the duplex oxide allowed carbon to accumulate at the metal–oxide interface, where dislocation activity introduced by pre‑straining and sustained creep facilitated transport; under creep, continued dislocation motion enabled deeper subsurface penetration compared with pre‑strained specimens. In contrast, 600‑grit ground surfaces initially formed a thin chromia film and, when this film was disrupted, developed a discontinuous duplex oxide. The associated near‑surface deformation and high dislocation density are proposed to promote local trapping of carbon close to the interface; once the ∼1–2 µm ultrafine‑grained layer (UFGL) is consumed, carbon diffusion into the bulk proceeds more slowly, such that only very limited carburisation is observed even under creep. Overall, the results highlight that dislocation activity and loading history govern both oxidation behaviour and the extent of carbon ingress.
{"title":"The effect of surface preparation and stress on oxidation and carburisation of 316 H stainless steel in CO/CO2 conditions","authors":"James Rafferty , Sándor Palkó , Marc Chevalier , Robert Ainsworth , Fabio Scenini","doi":"10.1016/j.corsci.2026.113667","DOIUrl":"10.1016/j.corsci.2026.113667","url":null,"abstract":"<div><div>This study demonstrates how surface preparation and mechanical loading affect oxidation and carburisation in 316 H stainless steel exposed to CO/CO₂ environments. OPS‑polished surfaces exhibited the greatest susceptibility, forming thick duplex oxides that enabled carbon ingress and substantial hardening, particularly under creep at 350 MPa. The permeability of the duplex oxide allowed carbon to accumulate at the metal–oxide interface, where dislocation activity introduced by pre‑straining and sustained creep facilitated transport; under creep, continued dislocation motion enabled deeper subsurface penetration compared with pre‑strained specimens. In contrast, 600‑grit ground surfaces initially formed a thin chromia film and, when this film was disrupted, developed a discontinuous duplex oxide. The associated near‑surface deformation and high dislocation density are proposed to promote local trapping of carbon close to the interface; once the ∼1–2 µm ultrafine‑grained layer (UFGL) is consumed, carbon diffusion into the bulk proceeds more slowly, such that only very limited carburisation is observed even under creep. Overall, the results highlight that dislocation activity and loading history govern both oxidation behaviour and the extent of carbon ingress.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113667"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-02DOI: 10.1016/j.corsci.2026.113682
Atharva S. Chikhalikar, Nico Tweedy, Yu-Hsuan Lin, David L. Poerschke
The high-temperature corrosion of FeCrAlY (forming Al2O3 TGO) and Haynes-214 alloys (forming Ni(Cr,Al)2O4 + Al2O3 TGOs) was studied under oxide, oxide-sulfate, and sulfate deposits at 1025 °C in dry air or air + 10 ppm SO2 atmosphere. SiO2-containing deposits adhered without major reactions, while CaSO4 formed calcium aluminates on FeCrAlY regardless of pre-oxidation. Mixed sulfate deposits reacted with all pre-oxidized FeCrAlY similarly, but the non-pre-oxidized samples showed greater Cr and Fe oxidation and sulfidation before Al2O3 passivation. On Haynes-214, 100 h pre-oxidation limited attack to surface products, whereas shorter or no pre-oxidation caused severe internal attack with internal oxidation and sulfidation that was accelerated under SOx atmospehere.
{"title":"Mechanistic underpinning of the effect of gaseous sulfur dioxide, thermally grown oxide structure, and pre-oxidation time on the mixed deposit-induced hot corrosion of alumina-forming alloys","authors":"Atharva S. Chikhalikar, Nico Tweedy, Yu-Hsuan Lin, David L. Poerschke","doi":"10.1016/j.corsci.2026.113682","DOIUrl":"10.1016/j.corsci.2026.113682","url":null,"abstract":"<div><div>The high-temperature corrosion of FeCrAlY (forming Al<sub>2</sub>O<sub>3</sub> TGO) and Haynes-214 alloys (forming Ni(Cr,Al)<sub>2</sub>O<sub>4</sub> + Al<sub>2</sub>O<sub>3</sub> TGOs) was studied under oxide, oxide-sulfate, and sulfate deposits at 1025 °C in dry air or air + 10 ppm SO<sub>2</sub> atmosphere. SiO<sub>2</sub>-containing deposits adhered without major reactions, while CaSO<sub>4</sub> formed calcium aluminates on FeCrAlY regardless of pre-oxidation. Mixed sulfate deposits reacted with all pre-oxidized FeCrAlY similarly, but the non-pre-oxidized samples showed greater Cr and Fe oxidation and sulfidation before Al<sub>2</sub>O<sub>3</sub> passivation. On Haynes-214, 100 h pre-oxidation limited attack to surface products, whereas shorter or no pre-oxidation caused severe internal attack with internal oxidation and sulfidation that was accelerated under SO<sub>x</sub> atmospehere.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113682"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-09DOI: 10.1016/j.corsci.2026.113707
Zewei Gu , Zhongheng Fu , Xinzheng Zhang , Tianchen Zhang , Tian Zhang , Jiamin Pei , Suyu Jin , Dominik Legut , Philippe Marcus , Dawei Zhang
Atomic-scale mechanisms by which chloride ions (Cl−) destabilize cuprous oxide (Cu2O) films and trigger pitting on copper (Cu) remain challenging to resolve under realistic hydration. Here, density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations are combined to interrogate Cu/Cu2O/water interfaces and to construct a unified solvent-resolved picture of Cl−-mediated depassivation. We identify an intrinsic oxygen-layer shielding effect on Cu2O(111) that limits direct water coordination to saturated surface Cu sites and contributes to film stability. Cl− destabilizes Cu2O through two coupled steps. Specifically adsorbed Cl− attenuates oxygen shielding, activates surface Cu sites, and cooperates with interfacial water to promote localized dissolution-like Cu detachment while perturbing interfacial water organization. This process exhibits a coverage threshold and is insensitive to film thickness. Substitutional Cl− at Cu/Cu2O interface migrates upward, draws neighboring coordinatively unsaturated Cu, induces concerted lifting of adjacent saturated Cu, and increases surface-oxygen hydrogen affinity, enhancing hydroxylation and facilitating cathodic reactions. Adsorbed and substitutional Cl− act synergistically at subthreshold Cl− concentrations with the combined destabilization dependent on Cu2O thickness. Thinner films fail at lower Cl− concentrations, whereas thicker films require higher adsorption coverages for breakdown. After film rupture, Cl− adsorption on exposed Cu(111) lowers the Cu dissolution barrier and restructures interfacial water, hindering Cu2O re-formation. These results distinguish adsorption- versus substitution-driven roles of Cl− and provide an atomistic framework for Cl−-induced depassivation and pitting initiation.
{"title":"First-principles insights into the chloride ion-mediated destabilization of cuprous oxide films in aqueous environment","authors":"Zewei Gu , Zhongheng Fu , Xinzheng Zhang , Tianchen Zhang , Tian Zhang , Jiamin Pei , Suyu Jin , Dominik Legut , Philippe Marcus , Dawei Zhang","doi":"10.1016/j.corsci.2026.113707","DOIUrl":"10.1016/j.corsci.2026.113707","url":null,"abstract":"<div><div>Atomic-scale mechanisms by which chloride ions (Cl<sup>−</sup>) destabilize cuprous oxide (Cu<sub>2</sub>O) films and trigger pitting on copper (Cu) remain challenging to resolve under realistic hydration. Here, density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations are combined to interrogate Cu/Cu<sub>2</sub>O/water interfaces and to construct a unified solvent-resolved picture of Cl<sup>−</sup>-mediated depassivation. We identify an intrinsic oxygen-layer shielding effect on Cu<sub>2</sub>O(111) that limits direct water coordination to saturated surface Cu sites and contributes to film stability. Cl<sup>−</sup> destabilizes Cu<sub>2</sub>O through two coupled steps. Specifically adsorbed Cl<sup>−</sup> attenuates oxygen shielding, activates surface Cu sites, and cooperates with interfacial water to promote localized dissolution-like Cu detachment while perturbing interfacial water organization. This process exhibits a coverage threshold and is insensitive to film thickness. Substitutional Cl<sup>−</sup> at Cu/Cu<sub>2</sub>O interface migrates upward, draws neighboring coordinatively unsaturated Cu, induces concerted lifting of adjacent saturated Cu, and increases surface-oxygen hydrogen affinity, enhancing hydroxylation and facilitating cathodic reactions. Adsorbed and substitutional Cl<sup>−</sup> act synergistically at subthreshold Cl<sup>−</sup> concentrations with the combined destabilization dependent on Cu<sub>2</sub>O thickness. Thinner films fail at lower Cl<sup>−</sup> concentrations, whereas thicker films require higher adsorption coverages for breakdown. After film rupture, Cl<sup>−</sup> adsorption on exposed Cu(111) lowers the Cu dissolution barrier and restructures interfacial water, hindering Cu<sub>2</sub>O re-formation. These results distinguish adsorption- versus substitution-driven roles of Cl<sup>−</sup> and provide an atomistic framework for Cl<sup>−</sup>-induced depassivation and pitting initiation.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113707"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-04DOI: 10.1016/j.corsci.2026.113677
Qiuyue Leng , Maokun Bai , Dapeng Yang , Junlong Zhou , Hongliang Yi
Press-hardening steels (PHS) with tensile strengths exceeding 1500 MPa are susceptible to hydrogen-induced delayed fracture (HIDF), posing challenges for automotive applications. Currently, constant load testing in hydrochloric acid (HCl) is widely used to assess HIDF risk, based on the assumption that hydrogen adsorbed via Volmer reaction diffuses into substrate and triggers fracture. However, existing studies have not demonstrated whether hydrogen generated from the reaction between steel and HCl can effectively penetrate substrate. Furthermore, industrial applications reveal ambiguous results when using HCl immersion method to evaluate HIDF risk. In this study, four-point bending tests under HCl immersion were performed on bare and Al-Si coated 2000MPa-grade PHS. Corrosion behavior and hydrogen evolution were examined using scanning electron microscopy (SEM) and thermal desorption analysis (TDA). Both specimens exhibit severe surface corrosion in HCl solution. While trace hydrogen ingress occurs initially, corrosion promotes effusion, preventing inward diffusion. Consequently, hydrogen concentration drops below 0.03 wppm within 10 h and remains stable. Despite these low levels, fractures still occur. Fractographic analysis reveals cleavage and microvoid coalescence without hydrogen embrittlement features. Notably, corrosion pits are observed in tensile region, particularly near laser-cut edges. Finite element analysis (FEA) confirms that pits induce stress concentrations exceeding a factor of 2. These findings indicate that fractures in this context are caused by pit-induced stress concentration rather than HIDF. The results challenge validity of current HCl immersion for assessing HIDF risk in PHS, as it fails to distinguish between corrosion-driven failure and hydrogen embrittlement, leading to misjudgment of actual HIDF risk.
{"title":"Reassessing the HCl immersion method for evaluating hydrogen-induced delayed fracture in press-hardening steels: Pit-induced stress dominance over hydrogen embrittlement","authors":"Qiuyue Leng , Maokun Bai , Dapeng Yang , Junlong Zhou , Hongliang Yi","doi":"10.1016/j.corsci.2026.113677","DOIUrl":"10.1016/j.corsci.2026.113677","url":null,"abstract":"<div><div>Press-hardening steels (PHS) with tensile strengths exceeding 1500 MPa are susceptible to hydrogen-induced delayed fracture (HIDF), posing challenges for automotive applications. Currently, constant load testing in hydrochloric acid (HCl) is widely used to assess HIDF risk, based on the assumption that hydrogen adsorbed via Volmer reaction diffuses into substrate and triggers fracture. However, existing studies have not demonstrated whether hydrogen generated from the reaction between steel and HCl can effectively penetrate substrate. Furthermore, industrial applications reveal ambiguous results when using HCl immersion method to evaluate HIDF risk. In this study, four-point bending tests under HCl immersion were performed on bare and Al-Si coated 2000MPa-grade PHS. Corrosion behavior and hydrogen evolution were examined using scanning electron microscopy (SEM) and thermal desorption analysis (TDA). Both specimens exhibit severe surface corrosion in HCl solution. While trace hydrogen ingress occurs initially, corrosion promotes effusion, preventing inward diffusion. Consequently, hydrogen concentration drops below 0.03 wppm within 10 h and remains stable. Despite these low levels, fractures still occur. Fractographic analysis reveals cleavage and microvoid coalescence without hydrogen embrittlement features. Notably, corrosion pits are observed in tensile region, particularly near laser-cut edges. Finite element analysis (FEA) confirms that pits induce stress concentrations exceeding a factor of 2. These findings indicate that fractures in this context are caused by pit-induced stress concentration rather than HIDF. The results challenge validity of current HCl immersion for assessing HIDF risk in PHS, as it fails to distinguish between corrosion-driven failure and hydrogen embrittlement, leading to misjudgment of actual HIDF risk.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113677"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-05DOI: 10.1016/j.corsci.2026.113691
Wenjun Ci , Qi Tao , Xianhua Chen , Carsten Blawert , Maria Serdechnova , Xiaohuan Pan , Chunquan Liu , Mikhail L. Zheludkevich
The addition of Dy significantly enhanced the corrosion resistance of EK3-xDy alloys (x = 0, 0.5, 1.0, 1.5 wt%), with the EK3–1.5Dy alloy exhibiting the lowest corrosion rate of 0.132 mm y−1, nearly an order of magnitude lower than that of the Dy-free alloy. Dy was found in solid solution in the Mg12Nd and Mg41Nd5 intermetallics forming Mg12(Nd, Dy) and Mg41(Nd, Dy), which acted as anodic sites and reduced the electrochemical potential difference with the magnesium matrix. The preferential dissolution of these anodic phases released Nd and Dy species that promoted the densification of the corrosion product film. As a result, a compact Dy2O3-Nd2O3-containing protective layer formed, substantially improving corrosion resistance.
添加Dy显著提高了EK3-xDy合金的耐蚀性（x = 0,0.5,1.0,1.5 wt%），其中EK3-1.5Dy合金的腐蚀速率最低，为0.132 mm y−1，比不添加Dy的合金低近一个数量级。Dy在Mg12Nd和Mg41Nd5金属间化合物中以固溶体形式存在，形成Mg12（Nd, Dy）和Mg41(Nd, Dy)，它们作为阳极位，减小了与镁基体的电化学电位差。这些阳极相的优先溶解释放出Nd和Dy，促进了腐蚀产物膜的致密化。从而形成致密的含有dy2o3 - nd2o3的保护层，大大提高了耐蚀性。
{"title":"Synergistic corrosion protection mechanism in Dy-modified EK3 alloys: Formation of anode phase and dense Dy-enriched corrosion product film","authors":"Wenjun Ci , Qi Tao , Xianhua Chen , Carsten Blawert , Maria Serdechnova , Xiaohuan Pan , Chunquan Liu , Mikhail L. Zheludkevich","doi":"10.1016/j.corsci.2026.113691","DOIUrl":"10.1016/j.corsci.2026.113691","url":null,"abstract":"<div><div>The addition of Dy significantly enhanced the corrosion resistance of EK3-xDy alloys (x = 0, 0.5, 1.0, 1.5 wt%), with the EK3–1.5Dy alloy exhibiting the lowest corrosion rate of 0.132 mm y<sup>−1</sup>, nearly an order of magnitude lower than that of the Dy-free alloy. Dy was found in solid solution in the Mg<sub>12</sub>Nd and Mg<sub>41</sub>Nd<sub>5</sub> intermetallics forming Mg<sub>12</sub>(Nd, Dy) and Mg<sub>41</sub>(Nd, Dy), which acted as anodic sites and reduced the electrochemical potential difference with the magnesium matrix. The preferential dissolution of these anodic phases released Nd and Dy species that promoted the densification of the corrosion product film. As a result, a compact Dy<sub>2</sub>O<sub>3</sub>-Nd<sub>2</sub>O<sub>3</sub>-containing protective layer formed, substantially improving corrosion resistance.</div></div>","PeriodicalId":290,"journal":{"name":"Corrosion Science","volume":"263 ","pages":"Article 113691"},"PeriodicalIF":7.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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