ZHANG Yun
,
LIU Yulin
,
ZHAO Hong' en
,
HU Zhuangqi
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaZHU Zhiyong
,
WANG Zhengfu
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China ZHANG Yun
,
Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The A1-2.79Li-1.3Cu-0.7Mg-0.12Zr(8090) alloy has excellent resistance to intergranular and exfoliation corrosion as naturally aged, worst as peak aged and rather better as underaged than as overaged. The corrosion behaviour of the alloy is closely dependent on its microstructure. Under the peak aging condition, the coarse T_2 phase, which is continuously distributed along grain boundaries, has so low corrosion potential in comparison with the ma- trix, this makes the corrosion resistance of the alloy to be deteriorated by anodic dissolution along grain boundaries.
关键词:
AI-Li alloy
,
null
,
null
,
null
J.H.Dong 1)
,
J.Y.Chen 2
,
3) and. C.N.Cao 1) 1) State Key Laboratory for Corrosion and Protection of Metals
,
Institute of Corrosion and Protection of Metals
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China 2) The International Center for Materials Physics
,
CAS
,
Shenyang 110015
,
China 3) Shenyang Normal College
,
Shenyang 110031
,
China
金属学报(英文版)
The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cathodic processes at corrosion potential. It has been shown that the major synergistic inhibition effects between amines and chloride ions occur in the cathodic process, very weak in the anodic process. The anodic inhibition mechanism follows the competing adsorptive model, while the cathodic inhibition mechanism follows the cooperative adsorptive model.
关键词:
synergistic inhibition
,
null
,
null
HUANG Qizhong
,
YANG Qzaoqin and WU Lijun(Powder Metallurgy Research institute
,
Central Sonth University of Technology
,
Changsha 410083
,
China Materials Research and Test Center
,
Hnnan University
,
Changsha 410082
,
ChinaLab. of Atomic Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang110015
,
ChinaState Key Laboratory for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)Manuscript received 4 August 1995
,
in revised form 6 April 1996
金属学报(英文版)
A Preliminary study of the effect of silicon additive on the structure and properites of C-B_4C-SiC composite was conducted. A liquid Phase has formed and the liquid Si reacts with C to form SiC at the grain boundary when sintering, which accelerates the sintering process and retards the grain growth. Consequently, the density and strength of the composite increase markedly. And the increase in the density increases the oxidation resistance and decreases the specific resistance of the composite. Furthermore,the C-B_4 C-SiC composite has good heat-shock resistance. The phenomena may be dueto the strengthening and toughening of microcracks.
关键词:
:Si additive
,
null
,
null
Yan NIU
,
Weitao WU and Chaoliu ZENG (State Key Lab. for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)F. Gesmundo and F. Viani (Instituto di Chimica
,
Facolta di Ingegneria
,
Un
材料科学技术（英）
The corrosion of an Fe-based alloy containing 15 wt pct Y in H2-H2S mixtures under 10-3 Pa S2 was studied at 600~800℃ in an attempt to find materials with improved sulphidation resistance with respect to pure Fe. The presence of Y has been shown to be beneflcial, but not sufficient to the level expected. In fact, the alloy is able to form at all tested temperatures an external FeS layer, beneath which a zone containing a mixture of the two sulphides is also present. Thus,Fe can still diffuse through this region to form the outer FeS layer with non-negligible rate. The corrosion rate of Fe is considerably reduced by the Y addition. but the alloy corrodes still much more rapidly than Y. The sulphidation kinetics is generally rather irregular for both the pure metals, while the corrosion rate of the alloy decreases with time and tends to become parabolic after an initial period of 12~17 h. The sulphidation behaviour of the alloys is discussed by taking into account the presence of an intermetallic compound Fe17Y2 and the limited solubility of Y in Fe
关键词:
Zhengfu WANG
,
Jin LI
,
Jianqiu WANG and Wei KE(Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang
,
110015
,
China)
材料科学技术（英）
The paper reports the effect of0.01,0.1 and 1%NaNO2, a passive inhibitor, on corrosion fatigue (CF) crack initiation and propagation for a low strength structural steel A537 in 3.5%NaCl aqueous solution. The experimental results show that inhibitor increases the required cycles of CF crack initiation effectively, and this effect increases with increasing inhibitor concentration.However, there is nearly no effect of NaNO2 on CF crack propagation. The same CF crack propagation rate was found in all kinds of solutions. The results also indicate that the passive time in 1%NaNO2 solution during plastic deformation is much longer than cyclic time. NaNO2 passivates the specimen sudece and repairs passive film damaged by cyclic loading during the crack initiation. while the passsive film is not formed fully due to continuous plastic deformation at the crack tip during the CF crack propagation, which is much different from that in the stress corrosion cracking and general corrosion
关键词:
S.G. Tian
,
L.T. Zhang
,
H. M. Shao
,
L.J. Zou
,
T.F. Li
,
and H. C. Yang (Department of Materials Science
,
Shenyang Polytechnic University
,
Shenyang 110023
,
China) (Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy ofSciences
,
Shenyang 110015
,
China) (Department of Materials Science
,
Northeastern University
,
Shenyang 110006
,
China)
金属学报(英文版)
In this paper, internal oxidation kinetics and the diffusion mechanism of oxygen in sintered Cu-Al alloy have been studied by means of scanning electron microscopy,transmission electron microscopy and heat-weighting scales. The results show that the kinetic curves obey the parabolic law in the initial stage and are linear in the late stage.The oxygen atoms are mainly transported in the from of grain boundary diffusion and volume diffusion in the process of internal oxidation. The plastic deformation of Cu matrix around oxide particles increases the probability of [O] atoms moving in accordance with dislocation diffusion mechanism. Meanwhile, the activation energy and diffusion coefficient in the process of internal oxidation are evaluated by means of kinetic method so as to obtain the velocity equations of reacting interface moving in different stage.
关键词:
: Cu-Al alloy
,
null
,
null
Zhengfu WANG
,
Xuejun WEI
,
Jin LI and Wei KE(State Key Lab. for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
材料科学技术（英）
The transient current behaviour for Iron in 3.5%NaCl and 3.5%NaCl +1%NaNO2 solutions during corrosion fatigue (CF) process has been investigated at different given strain amplitudes and strain rates. The results show that elastic strain has little contribution to material dissolution. The elastic tension strain results in the decrease in the transient current, while the elastic compression strain increases the transient current. Compared to the elastic deformation, plastic deformation affects material dissolution evidently For iron in 3.5%NaCl solution, the strain amplitude plays a dominant role in the dissolution process accelerated by the plastic strain, while in 3.5%NaCl+1%NaNO2 solution, both the strain amplitude and strain rate play an important role in this process. In this paper, the effect of the elastic deformation on the material dissolution and the relation between the tension and compression current peak values under the plastic cycle deformation are discussed
关键词:
F. Gesmundo
,
Y Niu
,
F. Vianiand D.L. Douglass(Universita di Genova
,
Fiera del Mare
,
Pad. D
,
16129 Genova
,
Italy)(State Key Lab. for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
theChinese Academy of Sciences
,
Shenyang 110015
,
China)(University of Arizona
,
4715 East Fort Lowell Road
,
TUcson
,
AZ 85712
,
USA)
金属学报(英文版)
The cormsion in air of a two-phase Cu-75Cr alloy was studied at 700-900℃. Thealloy cormded nearly parabolically at 700-800℃, but at 900℃ its instantaneousparabolic mte constant decreased with time. The scales were complex and consistedof an outermost layer of copper oxide generally followed bg a layer of the double ox-ide Cu2 Cr2 O4 sometimes containing particles of unoxidized chromium surmunded bya chromia layer. An innermost layer of chromia was also observed in some cases.Finally metallic copper was al8o frequently mixed with chromia particles. No Cr de-pletion was observed in the alloy close to the inteffoce with the scale. In any case,this alloy was not able to form an exclusive continuous protective chromia layer. Thespecial cormsion behavior Of this alloy is typical of two-phase binary systems with alange solubility gaP in which the outwaof dthesion fiux of the most-reactive componentin the alloy is strongly reduced and may be inswncient to fOrm a protective externallayer of the cormsponding oxide. In paTticular, the presence of particles of Cr withina double oxide layer is very unusual and is allowed only for the kinetic reason.
关键词:
copper-chromium
,
null
,
null
,
null
