Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The ...Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate.X-ray diffraction(XRD)patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along(200)facet.In addition,it is found that the incorporated SiC particles with medium micron sizes(8 and 1.5μm)could significantly enhance the micro-hardness of the Ni composite coatings.Nevertheless,electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced.In contrast,the combined incorporation of nanosized(50 nm)SiC particles with medium micron(1.5μm)ones is capable of promoting the compactness of the composite coatings,which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss.展开更多
In the present work,the distribution of sulfate-reducing-bacteria(SRB)inside the crevice and the effect of crevice width on SRB-induced corrosion of stainless steel 316L(SS 316L)were systematically investigated.A camb...In the present work,the distribution of sulfate-reducing-bacteria(SRB)inside the crevice and the effect of crevice width on SRB-induced corrosion of stainless steel 316L(SS 316L)were systematically investigated.A cambered crevice configuration consisting of a convex lens and a wire beam electrode(WBE)was employed to measure the current and potential distributions under different crevice widths.Subsequently,scanning electronic microscopy(SEM),electrochemical impedance spectroscopy(EIS)and X-ray photoelectron spectroscopy(XPS)were adopted to study SRB-induced corrosion behavior of SS 316L in different crevice locations.Results show that crevice width plays an essential role in corrosion on SS 316L in crevice environment with SRB.The most severe corrosion with dense pits occurred at the crevices with 150μm in width due to the combined effects of microbiological corrosion and crevice corrosion.In narrow crevices,corrosion is much slighter since SRB can hardly enter into the crevices to induce corrosion.In contrast,the crevices with 700μm in width suffer the mildest corrosion because the influence of crevice corrosion is negligible with a weakened crevice corrosion tendency.Additionally,it was found that SRB could affect the composition of the passive film and destroy its compactness,thus accelerate the crevice corrosion of SS 316L in artificial seawater.The findings of this work are beneficial to understanding the mechanisms of MIC-induced corrosion in various environments.展开更多
基金This work was financially supported by National Natural Science Foundation of China(Nos.51901018 and 51771027)National Science and Technology Resources In-vestigation Program of China(No.2019FY101400)+3 种基金Funda-mental Research Funds for the Central Universities,China(Nos.FRF-MP-19-001 and FRF-AT-20-07)National Key Research and Development Program of China(No.2017YFB0702100)China Postdoctoral Science Foundation(No.2019M660456)Young Elite Scientists Sponsor-ship Program by China Association for Science and Techno-logy(YESS,No.2019QNRC001).
文摘Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate.X-ray diffraction(XRD)patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along(200)facet.In addition,it is found that the incorporated SiC particles with medium micron sizes(8 and 1.5μm)could significantly enhance the micro-hardness of the Ni composite coatings.Nevertheless,electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced.In contrast,the combined incorporation of nanosized(50 nm)SiC particles with medium micron(1.5μm)ones is capable of promoting the compactness of the composite coatings,which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss.
基金financially supported by the National Natural Science Foundation of China(Nos.51771027,51901018)the Fundamental Research Funds for the Central Universities(Nos.FRF-AT-20-07,06500119)+2 种基金the Natural Science Foundation of Beijing Municipality(No.2212037)the National Science and Technology Resources Investigation Program of China(No.2019FY101400)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2019QNRC001)
文摘In the present work,the distribution of sulfate-reducing-bacteria(SRB)inside the crevice and the effect of crevice width on SRB-induced corrosion of stainless steel 316L(SS 316L)were systematically investigated.A cambered crevice configuration consisting of a convex lens and a wire beam electrode(WBE)was employed to measure the current and potential distributions under different crevice widths.Subsequently,scanning electronic microscopy(SEM),electrochemical impedance spectroscopy(EIS)and X-ray photoelectron spectroscopy(XPS)were adopted to study SRB-induced corrosion behavior of SS 316L in different crevice locations.Results show that crevice width plays an essential role in corrosion on SS 316L in crevice environment with SRB.The most severe corrosion with dense pits occurred at the crevices with 150μm in width due to the combined effects of microbiological corrosion and crevice corrosion.In narrow crevices,corrosion is much slighter since SRB can hardly enter into the crevices to induce corrosion.In contrast,the crevices with 700μm in width suffer the mildest corrosion because the influence of crevice corrosion is negligible with a weakened crevice corrosion tendency.Additionally,it was found that SRB could affect the composition of the passive film and destroy its compactness,thus accelerate the crevice corrosion of SS 316L in artificial seawater.The findings of this work are beneficial to understanding the mechanisms of MIC-induced corrosion in various environments.
