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Journal of Rare Earths 2022年第6期40卷 1002-1006,I0006页

作者： Farzaneh Khast Mesbah Saybani Ali Asghar Sarabi Dariani Corrosion Engineering and Material Protection Group Bandar Abbas CampusAmirkabir University of TechnologyTehranIran Department of Maritime Engineering Amirkabir University of TechnologyTehranIran Department of Color and Polymer Engineering Amirkabir University of TechnologyTehranIran

The cerium conversion coating(CeCC) containing copper and manganese cations was applied to the galvanized steel.The microstructure and the composition of specimen were analyzed by field emission scanning electron microscopy(FE-SEM) and energy dispersive spectroscopy(EDS).Electrochemical impedance spectroscopy(EIS) and polarization tests were conducted in 3.5 wt% NaCl solution to investigate the coating corrosion resistance.The results show that there are improvements in corrosion resistance and microstructure of CeCC containing copper and manganese cations but copper ions increase corrosion resistance of CeCC from 5800 to 27000 Ω·cm^(2).

关键词： Conversion coating galvanized steel EIS Copper Manganese Rare earths

Corrosion behavior and mechanism of the automotive hot-dip galvanized steel with alkaline mud adhesion

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 414-421页

作者： Hong Zhang Xiao-gang Li Cui-wei Du Hui-bin Qi School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Institute of Welding and Surface Technology Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

The corrosion behavior and mechanism of hot-dip galvanized steel and interstitial-free （IF） substrate with alkaline mud adhesion were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, electrochemical impedance spectroscopy （EIS）, and linear polarization. The results show that non-uniform corrosion occurs on the galvanized steel and IF substrate during 250 h with the mud adhesion. The corrosion products on the galvanized steel are very loose and porous, which are mainly ZnO, Zn5（OH）8C12·H2O and Zn（OH）2, and Fe-Zn alloy layer with a lower corrosion rate is exposed on the galvanized steel surface; however, the corrosion products on IF substrate are considerably harder and denser, whose compositions of rust are mainly FeOOH and Fe3O4, and several pits appear on their surface. The results of continuous EIS and linear polarization measurements exhibit a corrosion mechanism, that is, under activation control, the charge transfer resistances present different tendencies between the galvanized steel and IF substrate; in addition, the evolution of linear polarization resistances is similar to that of charge transfer resistances. The higher contents of dissolved oxygen and Cl^- ions in the mud play an important role in accelerating the corrosion.

关键词： corrosion mechanism galvanized steel interstitial-free （IF） steel mud adhesion

Study on lanthanum salt conversion coating modified with citric acid on hot dip galvanized steel

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Journal of Rare Earths 2010年第3期28卷 461-465页

作者：孔纲刘玲艳卢锦堂车淳山钟正 School of Materials Science and Engineering South China University of Technology

Modified lanthanum salt conversion coatings prepared by rare earth salt route based on lanthanum nitrate solution were proposed as alternatives to the process involving toxic hexavalent chromate.The structure and composition of the coating were determined with X-ray energy dispersive spectrometer and X-ray photoelectron spectroscopy.The surface morphologies of the treated samples were observed with scanning electron microscopy.The natural salt spray and electrochemical impendence spectra tests were carried ...

关键词： lanthanum galvanized steel corrosion resistance rare earths

Cerium-tannic acid passivation treatment on galvanized steel

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Rare Metals 2009年第3期28卷 284-288页

作者： LIU Guangming YU Fei YANG Liu TIAN Jihong DU Nan Key Laboratory of Nondestructive Testing （Nanchang Hangkong University） Ministry of Education of China Nanchang 330063 China School of Aeronautic and Mechanical Engineering Nanchang Hangkong University Nanchang 330063 China

A novel cerium-tannic acid passivation treatment was performed on galvanized steel. The corrosion resistance of cerium-tannic passivated samples was tested by dropping test with 0.5 wt.% CuSO4 aqueous solution. The mass loss per unit area of passivated samples was measured after the corrosion in 0.5 mol/L NaCl ＋ 0.005 mol/L H2SO4 at room temperature for 96 h. The electrochemical behaviors of cerium, tannic acid, and cerium-tannic acid passivated samples on galvanized steel in 0.5 mol/L NaCl solution were investigated by polarization curves and electrochemical impendence spectra. The corrosion equivalent circuit was established according to the impedance characteristics. The results show that cerium-tannic acid treated samples exhibit better corrosion resistance than the sole cerium or tannic acid treated samples under the same condition. The mechanism of synergistic effect for cerium-tannic acid passivation on galvanized steel was discussed.

关键词： passivation cerium tannic acid galvanized steel corrosion

Rare earth and silane as chromate replacers for corrosion protection on galvanized steel

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Journal of Rare Earths 2009年第1期27卷 159-163页

作者：彭天兰满瑞林 School of Chemistry and Chemical Engineering Central South University

The present work aimed at using rare earth lanthanum salt and trimethoxy（viny）silance as chromate substitutes for galvanized steel passivation, in contrast to zinc coating samples treated with chromate.The corrosion resistance was assessed by electrochemical impedance spectroscopy（EIS） and neutral salt spray tests（NSS）.Scanning electron microscopy（SEM） was used to characterize the sample surfaces.The organic coating adhesion on the panel was also investigated via varnishes-cross cut tests.The results indicated that rare earth and silane two-step treatment gave more effective anticorrosion performance than Cr, which also provided good paint adhesion.The coating formation mechanism was also discussed.

关键词： silane corrosion lanthanum galvanized steel rare earths

Investigation of Surface Damage in Forming of High Strength and galvanized steel Sheets

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Journal of Materials Science & Technology 2009年第3期25卷 389-394页

作者： Zhongqi Yu Yingke Hou Haomin Jiang Xinping Chen Weigang Zhang School of Mechanical Engineering Shanghai Jiao Tong Univ. Shanghai 200240 China Baosteel Technology Center Baoshan Iron ＆： Steel Co. Ltd Shanghai 201900 China School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong Univ. Shanghai 200240 China

Powdering/exfoliating of coatings and scratching galvanized steels and high strength steels （HSS）, are the main forms of surface damage in the forming of which result in increased die maintenance cost and scrap rate. In this study, a special rectangular box was developed to investigate the behavior and characteristics of surface damage in sheet metal forming （SMF） processes. U-channel forming tests were conducted to study the effect of tool hardness on surface damage in the forming of high strength steels and galvanized steels （hot-dip galvanized and galvannealed steels）. Experimental results indicate that sheet deformation mode influences the severity of surface damage in SMF and surface damage occurs easily at the regions where sheet specimen deforms under the action of compressive stress. Die corner is the position where surface damage initiates. For HSS sheet, surface damage is of major interest due to high forming pressure. The HSS and hot-dip galvanized steels show improved ability of damage-resistance with increased hardness of the forming tool. However, for galvannealed steel it is not the forming tool with the highest hardness value that performs best.

关键词： Surface damage Sheet metal forming High strength steel galvanized steel

Post treatment of silane and cerium salt as chromate replacers on galvanized steel

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Journal of Rare Earths 2009年第1期27卷 164-168页

作者：孔纲卢锦堂吴海江 School of Materials Science and Engineering South China University of Technology

A complex film on hot-dip galvanized steel sheet（HDG） was prepared by immersing the sheet in 0.1wt.% Ce（NO3）3 solution and 5vol.% silane solution in turn.The corrosion protection of the complex film was evaluated by potentiodynamic linear polarization（LPR）, electrochemical impendence spectra（EIS） and natural salt spray（NSS） tests and compared with that of single cerium film and silane film.The results showed that, the presence of these films on the zinc coating hindered corrosion reaction by reducing the rate of both anodic and cathodic reaction in the corrosion process, and the corrosion protection of the complex film was much better than that of single cerium film or silane film and closed to that of chromate film, because the polarization resistance Rp and electrochemical impendence were increased markedly.Microstructure and chemical composition of these pretreated films were also investigated by scanning electron microscopy（SEM） and AES.

关键词： cerium salt silane galvanized steel passivation rare earths

Structure and Corrosion Resistance of a Composite γ-Amino Propyl Triethoxy Silane and γ-Glycidoxy Propyl Trimethoxy Silane Conversion Coating on galvanized steel

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Journal of Iron and steel Research(International) 2012年第11期19卷 46-51页

作者： WANG Lei LIU Chang-sheng YU Hai-yun AN Cheng-qiang Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education Northeastern UniversityShenyang 110004LiaoningChina School of Environmental and Chemical Engineering Shenyang Ligong UniversityShenyang 110159LiaoningChina

In an aqueous solution of the mixtures of γ-amino propyl triethoxy silane and γ-glycidoxy propyl trimethoxy silane, a composite silane conversion coating was developed on galvanized steel. FESEM （field emission scanning electron microscope）, XPS （X-ray photoelectron spectroscopy）, ATR FTIR （attenuated total reflection Flourier transform infrared spectroscopy） and SST （salt spray test） were used to characterize the obtained composite silane conversion coating and also the coating formation process was studied. The result showed that the surface of the composite silane conversion coating was complete, consecutive and compact. The coating could endure a neutral salt spray test for 72 h without corrosion. The result of salt spray test indicated that the composite silane conversion coating can provide a better corrosion inhibition than the coating which was composed of the single silane. Based on observation and analysis, it was proposed that the formation process of the silane coating on zinc should consist of three steps： the hydrolysis of the silane molecules, silane chemical adsorption and silane crosslinking condensation. The crosslinking reactions took place between ~＇-amino propyl triethoxy and ＂/-glycidoxy propyl trimethoxy silane during the forming process of the coating, and a high crosslinked density interpenetrating structure network was obtained, so the composite silane conversion coating could keep the corrosive substances from the zinc more effectively.

关键词： galvanized steel composite silane conversion coating structure forming process corrosion resistance

MICROSTRUCTURE AND PROPERTIES OF DEEP CROGENIC TREATMENT ELECTRODES FOR SPOT WELDING HOT DIP galvanized steel

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Chinese Journal of Mechanical Engineering 2005年第1期18卷 17-20页

作者： WuZhisheng LiuCuirong WangJiuhai ShanPing HuShengsun LianJinrui SchoolofMaterialsScience TaiyuanUniversityofScienceandTechnologyTaiyuan030024China SchoolofMaterialsScience TianjinUniversityTianjin300072China

The microstructure and elements distribution of the deep cryogenic treatmentelectrodes and non-cryogenic treatment electrodes for spot welding hot dip galvanized steel areobserved by a scanning electrical microscope. The grain sizes, the resistivity and the hardness ofthe electrodes before and after deep cryogenic treatment are measured by X-ray diffraction, the DCdouble arms bridge and the Brinell hardness testing unit respectively. The spot welding processperformance of hot dip galvanized steel plate is tested and the relationship between microstructureand physical properties of deep cryogenic treatment electrodes is analyzed. The experimental resultsshow that deep cryogenic treatment makes Cr, Zr in deep cryogenic treatment electrodes emanatedispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non-cryogenictreatment ones so that the electrical conductivity and the thermal conductivity of deep cryogenictreatment electrodes are improved very much, which make spot welding process performance of the hotdip galvanized steel be improved.

关键词： Deep cryogenic treatment Electrodes Microstructure Spot welding galvanized steel

Composition and Performance of the Composite Coatings Obtained by Phosphating and Cerium Nitrate Post-Sealing on galvanized steel

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Journal of Rare Earths 2007年第S1期25卷 461-464页

作者：林碧兰卢锦堂孔纲刘军 College of Material Science and Engineering South China University of Technology

To improve the corrosion resistance of phosphate coatings, the phosphated hot-dip galvanized (HDG) steel was post-sealed with cerium nitrate solution. The morphology, composition, corrosion resistance of the coatings was investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and neutral salt spray (NSS) tests. The results show that after post-sealing the phosphated HDG samples with cerium nitrate solution, the pores among the zinc phosphate crystals are sealed by the compounds containing phosphorus, oxygen and cerium; the zinc phosphate crystals are covered by the flocculent cerium compounds; and the continuous composite coatings are formed on HDG steel. The corrosion resistance of the composite coatings, which increases with the increase in phosphating time and cerium nitrate post-sealing time, is far higher than that of the single phosphate coatings. The composite coatings with the optimal corrosion resistance are obtained for phosphating 300 s and post-sealing 300 s; and the corrosion resistance is more outstanding than that of the chromate coatings.

关键词： galvanized steel phosphate coatings rare earths corrosion