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Energy Principle of Corrosion Environment Accelerating Crack Propagation During anodic dissolution Corrosion Fatigue

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Journal of Shanghai Jiaotong university(Science) 2013年第2期18卷 190-196页

作者：黄小光许金泉冯淼林 School of Navel Architecture Ocean and Civil EngineeringShanghai Jiaotong University College of Pipeline and Civil Engineering China University of Petroleum

A general method to predict the crack propagation of anodic dissolution corrosion fatigue is developed in this paper. Crack propagation of corrosion fatigue is presented as the result of the synergistic interactions of mechanical and environmental factors, and corrosive environment accelerates crack propagation mainly in term of anodic dissolution. By studying the variation of mechanical energy and electrochemical energy of anodic dissolution during the crack propagation process, an explicit expression of crack propagation rate is derived by the conservation of energy. The comparisons with experimental data demonstrate the validity of the proposed model. Moreover, the applicable upper-limit crack length for steady crack propagation is determined and the crack propagation life is evaluated.

关键词： crack propagation corrosion fatigue conservation of energy anodic dissolution

ELECTROCHEMICAL STUDIES ON anodic dissolution OF SYNTHETIC NICKEL SULFIDES

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Acta Metallurgica Sinica(English Letters) 1989年第9期2卷 159-166页

作者： FANG Zhaoheng CHEN Jiayong Institute of Chemical Metallurgy,Academia Sinica,Beijing,China CHEN Jiayong Institute of Chemical Metallurgy,Academia Sinica,Zhongguancun,Beijing,China

The anodic behavior of synthetic nickel sulfides in sulfuric acid solutions was *** the anodes of Ni_3S_2 ,Ni_7S_6 and NiS are actively dissolved respectively,a solid layer forms on the electrode surface with its nature and composition depending on the potentials applied. Based on the electrochemical phenomena,phase and elemental compositions of the solid layer formed on the electrode surface were *** apparent number of electrons transfer- red during dissolution of Ni^(2+)was also *** can be considered that there are three parallel reactions ocurred on the electrode:the reaction with formation of HSO_4^- or SO_4^(2-), the reaction with formation of sulfides as intermediates and the reaction of Jorming elemental *** NiS_2 as an anode,formation of SO_4^(2-)or HSO_4^- can be considered as the only re- action occurred on the electrode.

关键词： nickel sulfide anodic dissolution electrochemical behavior

Effect of Cl^-ion on anodic Iron dissolution in H_2S-Containing Sulfuric Acid Solutions

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Chinese Chemical Letters 1998年第10期9卷 945-948页

作者： Li Jing YAN Lin NIU Hat Chao LIN Wei Tao WU Shang Zhang LIU(Institute of Corrosion and Protection of Metals, State Key Laboratory for Corrosion and Protection, Chinese Academy of Sciences, Shenyang 110015Department of Chemistry, Liaoning University, S Inst. Corros. and Protect. of Met. State Key Lab. Corros. and Protect. Chinese Academy of Sciences Shenyang 110015 China Department of Chemistry Liaoning University Shenyang 110036 China

The effect of Cl- ion on the anodic iron dissolution in H2SO4 solutions containing H2S has been studied by using electrochemical polarization curve measurements. The competitive adsorption for Cl- and HS- ions at an anodic potential has been calculated using the CNDO/2method. The results show that a ceftain concentration of the Cl- ion can be adsorbed steadily and inhibit the anodic reaction of iron catalyzed by HS-. However, when the Cl- ion reaches the saturation adsorption, it begins to promote the anodic reaction of iron due tO the increased negative charge of iron atoms.

关键词： iron anodic dissolution Cl H_2S, CNDO/2

Investigation of stress corrosion cracking behavior and mechanism analysis of a 1900 MPa-grade ultra-high-strength stainless steel

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Journal of Iron and Steel Research International 2022年第9期29卷 1474-1484页

作者： Shuai Tian Zhen-bao Liu Ren-li Fu Xiao-hui Wang Jian-xiong Liang School of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016JiangsuChina Instiute for Special Steel Institute Central Iron and Steel Research InstituteBeijing 100081China

The stress corrosion cracking(SCC)behavior of a 1900 MPa-grade ultra-high-strength stainless steel in 3.5 wt.% NaCl solution was investigated by X-ray diffractometer,scanning electron microscopy,electron back-scattered diffraction,X-ray photoelectron spectroscopy,and potentiodynamic polarization *** results showed that USS122G stel has good SCC resistance,and the critical stress intensiy factor(K_(iscc))of USS122G steel was about 68.906 MPa m^(1/2) and Kiscc/K_(ic)=0.76(K_(ic) is plane strain fracture toughness).The existence of film-like austenite along the lath martensite boundary and the protective effect of thecc passivation flm were the main factors for its high *** them,the main components of the passivation film on the surface of USS122G steel were Cr_(2)O_(3),Cr(OH)_(3),FeOOH,and Ni(OH)_(2).The fracture morphology of SCC zone was intergranular and *** the slow and fast scanning rate polarization curve test results,it can be concluded that SCC mechanism of USS122G steel in 3.5 wt.%NaCl solution at the open-circuit potential was a mixed mechanism involving hydrogen embritlement and anodic dissolution.

关键词： Ultra-high-strength stainless steel.Critical stress intensity factor-Film-like austenite Hydrogen embrittlement anodic dissolution

What activates the Mg surface——A comparison of Mg dissolution mechanisms

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Journal of Materials Science & Technology 2020年第22期54卷 204-220页

作者： Jufeng Huang Guang-Ling Song Andrej Atrens Matthew Dargusch Center for Marine Materials Corrosion and Protection College of MaterialsXiamen UniversityXiamen 361005China State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen 361005China Centre for Advanced Materials Processing and Manufacturing School of Mechanical and Mining EngineeringThe University of QueenslandSt.LuciaQld 4072Australia

Several mechanisms have been proposed to interpret the widely reported phenomenon of Mg corrosion that the hydrogen evolution rate increases with increasing anodic potential or anodic current density. This paper critically analyzed the two main mechanisms,(1) "the incomplete film univalent Mg+ion mechanism" and(2) "the enhanced catalytic activity mechanism", aiming to clarify the current understanding of the Mg corrosion mechanism and to provide a profound insight into the Mg characteristic electrochemical behavior, anodic polarization accelerating both hydrogen evolution and Mg dissolution. It is expected that the deepened fundamental understanding from this comprehensive mechanistic review will provide a basis of practical applications for Mg alloys and open up a new way to the control of corrosion of Mg alloys in practice.

关键词： Magnesium Negative difference effect(NDE) Corrosion Hydrogen evolution anodic dissolution

Influence of the lithium content on the negative difference effect of Mg-Li alloys

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Journal of Materials Science & Technology 2020年第22期54卷 138-145页

作者： C.Q.Li D.K.Xu Z.R.Zhang E.H.Han School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The so-called 'negative difference effect'(NDE) was often defined by the increasing rate of hydrogen evolution from magnesium(Mg) surface under anodic *** this work,a series of electrochemical tests and microstructure observations were performed to provide an evidence that the NDE of Mg-Li alloys can be retarded by increasing lithium ***,galvanostatic and potentiodynamic polarization experiments using Mg-xLi(x=4,7.5 and 14 wt%) alloys electrodes indicated that Mg-4 Li alloy maintained the enhancing NDE prior to anodic dissolution as that of conventional Mg ***,the emergence of β-Li phase weakened the NDE of duplex Mg-7.5 Li alloy at a low anodic current density,but it was still enhanced apparently after a high applied anodic value(more than 2 mA/cm^2).The surface observations,including the plane and cross-sectional morphologies,confirmed that the cracked surface film derived from the anodic dissolution resulted in the catalytic activity of NDE for Mg-4 Li and Mg-7.5 Li ***,the NDE of Mg-14 Li alloy was suppressed obviously after a prior applied anodic polarization,which was attributed to the persistent and integrated surface film which endured a higher level of applied anodic potential and current.

关键词： Mg-Li alloy Negative difference effect Electrochemical property Corrosion anodic dissolution

A Mg alloy with no hydrogen evolution during dissolution

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Journal of Magnesium and Alloys 2023年第6期11卷 2084-2095页

作者： Fuyong Cao Bo Xiao Ziming Wang Tao Ying Dajiang Zheng Andrej Atrens Guang-Ling Song Center for Marine Materials Corrosion and Protection College of MaterialsXiamen University422 S.Siming Rd.Xiamen 361005China State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen University422 S.Siming RdXiamen 361005China National Engineering Research Center of Light Alloy Net Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Mechanical and Mining Engineering The University of QueenslandSt LuciaBrisbaneQLD 4072Australia

Hydrogen evolution is normally associated with the corrosion or dissolution of Mg alloys in aqueous *** work studied the corrosion behavior of sputtered pure Mg,Mg82Zn18(at.%),Mg64Zn36(at.%),and pure Zn in 3.5%Na Cl ***64Zn36had(ⅰ)an amorphous microstructure with some nano-scale grains,(ⅱ)a corrosion rate substantially lower than that of pure Mg,and(ⅲ)no hydrogen evolution during corrosion or anodic dissolution,because the positive corrosion potential retarded the cathodic hydrogen *** is a new route to prevent hydrogen evolution during Mg corrosion,which has never previously been realized.

关键词： Magnesium hydrogen evolution metal glass anodic dissolution

Experimental investigation into fabrication of microfeatures on titanium by electrochemical micromachining

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Advances in Manufacturing 2016年第2期4卷 167-177页

作者： Sandip S. Anasane B. Bhattacharyya Department of Production Engineering Jadavpur UniversityKolkata India

Titanium machining is one of the challenging tasks to modem machining processes. Especially fabricat- ing microfeatures on titanium appear as a potential research interest. Electrochemical micromachining （EMM） is an effective process to generate microfeatures by anodic dis- solution. Machining of titanium by anodic dissolution is different than other metals because of its tendency to form passive oxide layer. The phenomenon of progression of microfeature by conversion of passive oxide layer into transpassive has been investigated with the help of mask- less EMM technique. Suitable range of machining voltage has been established to attain the controlled anodic disso- lution of titanium by converting passive oxide film of titanium into transpassive with nonaqueous electrolyte. The experimental outcomes revealed that the micromachining of titanium with controlled anodic dissolution could be possible even at lower machining voltage in the range of 6-8 V. This work successfully explored the possibility of generation of microfeatures on commercially pure titanium by anodic dissolution process in microscopic domain by demonstrating successful fabrication of various microfea- tures, such as microholes and microcantilevers.

关键词： Titanium machining Electrochemicalmicromachining (EMM) anodic dissolution Currentdensity Current efficiency

BEHAVIOUR AND MECHANISM OF STRESS CORROSION CRACKING FOR Al-Li-Cu-Mg ALLOY

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Acta Metallurgica Sinica(English Letters) 1992年第11期5卷 391-395页

作者： WANG Zhengfu ZHU Ziyong KE Wei Corrosion Science Laboratory,Institute of Corrosion and Protection of Metals,Academia Sinica,Shenyang,ChinaZHANG Yun HU Zhuangqi Institute of Metal Research,Academia Sinica,Shenyang,China Inst of Corrosion and Protection of Metals Academia Sinica Shenyang China

Studies were made of the influence of aging conditions and applied potentials on the stress corrosion carcking(SCC)susceptibility for an Al-Li-Cu-Mg alloy by slow strain rate *** relationship between the relative hydrogen content on specimen surface,the applied potentials and elapsed time has also been *** SCC susceptibility was found to be dependent on aging conditions in which the peak aged condition gave the worst SCC resistance and the natural aged condition had the best one. The SCC susceptibility and surface hydrogen content relates to the applied potentials. The anodic potentials increase SCC susceptibility,while the cathodic ones below the critical potential accelerate *** is considered that both the anodic dissolution and

关键词： Al-Li alloy stress corrosion cracking anodic dissolution hydrogen embrittlement