氯氧镁水泥混凝土中钢筋的腐蚀与防护试验研究

结合氯氧镁水泥混凝土耐水性,研究氯氧镁水泥混凝土中钢筋的腐蚀与防护,试验变量包括钢筋种类、混凝土保护层厚度和腐蚀龄期等。钢筋种类包括裸露钢筋和美加力涂层钢筋;混凝土保护层厚度包括25、50 mm;腐蚀龄期包括60、120、180、240、300、360 d。试验采用自来水长期浸泡至试块2/3处,并采用扫描电子显微镜（SEM）和能谱仪（EDS）对腐蚀后的钢筋微观结构和化学元素组成进行分析,研究钢筋的腐蚀机理。结果表明,通过软化系数分析,氯氧镁水泥混凝土的软化系数处于0.78～0.87,说明试验设计的氯氧镁水泥混凝土可用于干燥地区、受潮较轻地区或次要建筑结构。通过极化曲线及其电化学参数分析,裸露钢筋腐蚀速率为美加力涂层钢筋腐蚀速率的40～80倍,说明涂层防腐效果明显。     

Potential’s fluctuation of rust preventing oil film during its degradation

Potential’s fluctuation of rust preventing oil film during its degradation was studied using wire beam electrode. Being non-destructive and simple, potential measurement is a very repetitive method. Other electrochemical testing method, e.g., polarization resistance, can breakdown the integrity of oil coating by DC current; EIS is time consuming. As a special electrochemical sensor, wire beam electrode contains 101 wires of mild steel wires, and it is helpful to improve the reproducibility of electrochemical test evidently. Using this electrode, the electrochemical parameters and their distribution which was related to underfilm corrosion process are measured directly so as to describe potential’s fluctuation of rust preventing oil film. It is pointed out that there is potential’s fluctuation on rust preventing oil film during its degradation, and this characteristic has direct effect on the self-repairing ability of rust preventing oil film. However, for the uncoated metal electrode and base oil film, there is no such behavior. It is also pointed out that inhibitors in the oil film have direct effect on its self-repairing ability. Project supported by the Natural Science Foundation of Hunan Province Synopsis of the first author Jiang Hangying, professor, born on July 4, 1928, majoring in Metallurgical Physicochemistry and Electrochemistry, have published about 100 papers.     

P-C法涂覆中碳结构钢的表面耐蚀性

应用Ｐ－Ｃ法对中碳结构钢进行Ｃｒ－Ｓｉ－Ａｌ复合涂覆,用电子探针及扫描电镜测定了涂层的表面成分及Ｃｒ,Ｓｉ,Ａｌ在涂层中的分布,用Ｘ射线衍测定了涂层中的相结构,将涂覆后的试样在酸、碱、盐溶液中进行腐蚀试验,结果表明,中碳结构钢经Ｐ－Ｃ法复合涂履后,表面优良的抗多种介质腐蚀的能力。     

纳米材料在无镀铜焊丝中的研究现状

无镀铜焊丝是未来气保护实芯焊丝的发展趋势.综述了纳米材料在无镀铜焊丝中的研究现状,得出:1)无镀铜焊丝表面的纳米涂层使自腐蚀电位正向增加,焊丝的耐蚀性增强;焊接时熔滴细化,熔滴过渡频率加快,电弧稳定性增强.2)纳米添加剂在摩擦界面通过物理吸附或摩擦化学反应成膜、"微滚珠"、"微抛光"等机制降低摩擦副的摩擦因数和磨斑直径,为减少无镀铜焊丝导电嘴磨损提供了理论指导.     

Effects of electroplated coatings on corrosion behavior of Ti-1023/30CrMnSiA galvanic couple

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled 30CrMnSiA steel was investigated in 3.5% NaCl solution. Particular attention was given to the effect of three different electroplated coatings on corrosion behavior of the galvanic couple. Galvanic corrosion test was conducted on Ti-1023 titanium alloy which coupled Ni-electroplated 30CrMnSiA, Zn-electroplated 30CrMnSiA, Cd-electroplated 30CrMnSiA and bare 30CrMnSiA, respectively. Corrosion properties including open circuit potential （Eoc）, galvanic corrosion potential （Eg）, and galvanic corrosion current （lg） were monitored. Corrosion morphology was observed by optical microscope （OM） and corrosion mechanism was analyzed and discussed. The results show that the three electroplated coatings improve the corrosion resistance of the anode in different magnitudes. Ni-electroplated 30CrMnSiA and Cd-electroplated 30CrMnSiA coatings are found to be least susceptible to galvanic corrosion when coupled Ti-1023 titanium alloy. Zn-electroplated 30CrMnSiA is moderately susceptible to galvanic corrosion. But the bare 30CrMnSiA is highly susceptible to galvanic corrosion in corrosive environment.     

X80钢及其焊缝在鹰潭土壤模拟溶液中的循环伏安行为

用循环伏安法研究了X80钢及其焊缝在鹰潭土壤模拟溶液中,溶液/电极界面上的电化学腐蚀反应。通过改变扫描速率、阳极电位上限、离子浓度、通气状态研究了钢的阳极极化和阴极析氢反应之间的相互作用。结果表明,酸性环境中的X80钢电化学行为是不可逆的电荷转移过程,钢的表面不能形成一个稳定的氧化膜。溶液中的侵蚀性离子使阳极极化和阴极析氢反应程度增加。阳极极化产生的稳定沉淀层对析氢反应起催化作用。氧气的存在能使钢表面能生成稳定的氧化膜,这会降低对析氢反应的催化作用。溶液中的CO2能增加焊缝的SCC敏感性。     

冷轧钢板表面清洁度对耐蚀性的影响

采用电化学测试和高低温交变湿热试验主要研究了轧制后和退火后的钢板的耐蚀性,分析了钢板表面清洁度对耐蚀性的影响,并探讨了实际生产过程中的影响因素.结果表明：轧制后的钢板的耐蚀性明显好于退火后的钢板;表面残留物明显地影响了轧制后钢板的耐蚀性分布的均匀性,清洗后的钢板的耐蚀性更好;退火后的钢板表面耐蚀性均匀性较差,清洗的钢板耐蚀性较未清洁的钢板更好;冷轧板表面清洁度问题是由原料—轧制—退火—储存过程中多因素的变量构成的,并直接影响其耐蚀性能.     

POTENTIAL'S FLUCTUATION OF RUST PREVENTING OIL FILM DURING ITS DEGRADATION

ManyelectricalandelectrochernicalmethodsareusedtostudyandevaluatetheprotectivenatureoforganiccoatingsL'~,j.Astheonlytrulynon--destructive,repetitivetestofalld.c.electrochemicaltechniquesfortestingthecorrosionprotectivequalityofcoatings,themeasurementofpotentialisquiteausefulmethodowingtoitssimplicityandeaseofmeasurement.AthoroughreviewofthismethodhasbeenmadebyWolstenholme[6);howeverallthosemethodsadoptbigsquaremetalelectrode,dependgreatlyupontheintegrityofthecoating.However,coatingsareinhomog…     

表面渗铝Q235钢在弱酸性卤水中的腐蚀与防护

应用电化学方法及形貌观察研究了表面渗铝Q235钢在弱酸性卤水中的腐蚀行为.结果表明:在Cl-浓度为0.3 mol/L,pH=6的40℃的NaCl溶液中,渗铝层起到了阻止Q235钢基体腐蚀的作用,渗铝层主要是由Al,Fe化合物组成.Q235表面腐蚀产物疏松、容易脱落,渗铝钢表面腐蚀产物致密、均匀.渗铝钢表层形成的Al,Fe化合物连续致密,具有高效保护作用,Al-Fe合金渗层起到阴极保护的作用.     

Effects of C,N-Codoped on the Corrosion Resistance of TiO_2 Films Prepared by Plasma Surface Alloying and Thermal Oxidation Duplex Process

C,N-codoped TiO 2 films have been deposited onto stainless steel substrates using plasma surface alloying and thermal oxidation duplex process.Composition analysis shows that the films shield the substrates entirely.The TiO 2 films are anatase in structure as characterized by X-ray diffraction.The electrochemical measurements show that the equilibrium corrosion potential positively shifts from-0.275 eV for bare stainless steel to-0.267 eV for C,N-codoped TiO 2 coated stainless steel,and the corrosion curren...     

低温烧结活性瓷釉涂层钢筋耐腐蚀性能试验研究

为了研究低温烧结活性瓷釉（LTCRE）涂层的性能和机理,利用差示扫描量热法（DSC）和热重法（TG）对LTCRE涂层的烧结温度进行优化,采用扫描电子显微镜（SEM）、X射线能谱分析（EDS）和X射线衍射（XRD）分析涂层微观结构和腐蚀过程,通过中性盐雾试验和氙灯老化试验研究LTCRE涂层钢筋的耐腐蚀性能. LTCRE涂层的优化烧结温度为500~540 °C,涂层具有结构致密、孔隙率低的特点,LTCRE涂层钢筋在腐蚀后的质量变化为普通钢筋的1.6%,800 h盐雾腐蚀后人为缺陷孔的剥离半径为0.26 mm,在氙灯照射下耐老化时长超过500 h. 结果表明,LTCRE涂层作为无机陶瓷涂层,具有比环氧树脂涂层更优异的耐老化性能,具备长期稳定的耐腐蚀能力. 涂层密实少孔的结构和烧结时良好的化学反应使得LTCRE涂层钢筋能够有效阻止外界腐蚀物质渗入与蔓延,即使在缺陷孔发生腐蚀后也能够阻止腐蚀加剧,起到涂层自愈合的效果.     

Nanophase formation and its behavior of corrosion resistance in C+Ti dual implanted steel

After corrosion and pitting corrosion, the wire nanometer phases are observed using a transmission electron microscope (TEM) in C + Ti dual implanted H13 steel. The property of corrosion resistance dual-implanted (C + Ti) H13 steel is studied using multi-sweep cyclic voltammetry. TEM images of the cross section of an implanted sample reveal plenty of circular nanometer structures with diameters of 10-30 nm. The phases are densely embedded in the implanted layer. The embedded structure improves the surface corrosion resistance, as can be observed with a scanning electron microscope (SEM). The phases with the shape of a tiny wire in nanometer size are formed. The nanometer phases, consisting of TiC, FeTi and FeTi2, are formed in dual implanted layer. The corrosion current peak density decreases to 1/16-1/10 that of the unimplanted H13 steel. The formation conditions of the nanometer phases and their effects are investigated. The passivation layer consists of nanometer phases. The corrosion resistance of th     

多相流动状态下原油对 X70钢 CO2腐蚀的影响

利用自制实验装置模拟起伏管路段塞流动条件下 X70钢 CO 2腐蚀问题,通过电子显微镜、腐蚀挂片等对挂片表面形貌、腐蚀速率情况进行分析,研究了多相流动状态下原油对 X70钢 CO 2腐蚀速率的影响。结果表明：油水反相点不能作为油水混输管线腐蚀临界点;原油对 X70钢腐蚀防护作用仅局限于均匀腐蚀,对局部腐蚀无防护作用,随着原油含量的增加,局部腐蚀速率可能升高;原油对均匀腐蚀的防护作用主要体现在：降低挂片表面润湿面积,减小挂片与腐蚀介质接触机会;增大腐蚀介质的混合黏度,降低挂片表面传质速度;高含蜡原油内的许多未知成分具有缓蚀作用。     

Improving corrosion resistance of Q235 steel by Ni-Cr alloyed layer

Ni-Cr alloyed layer was formed on surface of Q235 steel by double glow plasma surface metallurgy to improve the corrosion resistance of substrate. The composition and microstructure of alloyed layer was analyzed by SEM and XRD. Potentiodynamic polarization and electrochemical impedance spectroscopy was applied to evaluate the corrosion resistance of the alloyed layer. The results showed working pressure had a great effect on structure of Ni-Cr alloyed layer, and the dense and smooth alloyed layer was prepared at 50 Pa working pressure. Compared with substrate, Ni-Cr alloyed layer exhibited higher corrosion potential, lower corrosion current density and larger charge transfer resistance, which indicated that Ni-Cr alloyed layer significantly modified the corrosion resistance of Q235 steel.     

PHC管桩三种常用金属端头在土壤模拟液中的电化学腐蚀行为

金属端头的耐蚀性取决于其各部件(包括端板、裙板和主筋)的材质,进而影响预应力高强混凝土管桩(PHC管桩)的耐久性。通过自然浸泡和电化学测量技术研究了实际工程中PHC管桩三种常用金属端头(其中端板分别用铸钢、冷弯钢和Q235A钢)在四种典型土壤(氯盐土、盐碱土、中性草甸土和酸性红土)模拟液中的腐蚀行为。结果表明,实际工程所用端板的腐蚀速率均小于主筋和裙板,铸钢端板加速裙板和主筋腐蚀的程度不如冷弯钢或Q235A钢端板,但铸钢端板本身耐蚀性极差;端板与裙板、端板与主筋在土壤中存在接触电偶腐蚀,端板/裙板电偶对中裙板均为阳极,铸钢端板/主筋电偶对在盐渍土中铸钢为阳极,冷弯钢或Q235A钢端板与主筋电偶对中主筋也均为阳极;接触腐蚀加速了薄壁裙板和小面积主筋的破坏,将导致预应力的过早失效;现有金属端头需进行防腐蚀控制。     

XPS study of the corrosion resisting composite alloying layer obtained by double glow plasma with the brush plating Ni interlayer

The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brush plating Ni interlayer on the low carbon steel substrate has been investigated. By the electrochemical method in 3.5% (mass fraction) NaC1 solution, the corrosion resistance of the composite alloying layer and single alloying layer is determined. The experimental results show that the corrosion resistance of the composite alloying layer is obviously better than that of the single alloying layer. The structure and composition of passive films formed on the two kinds of alloyed layers after electrochemical tests in 3.5% NaC1 solution have been studied using X-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloying of low carbon steel with the electric brush plating Ni interlayer is an appropriate technique to enhance the corrosion resistance compared with the single double glow surface alloying.     

渗铬P110钢在CO2饱和模拟油田采出液中的耐蚀性

为了提高P110油套管钢的表面性能,以满足其在油田环境下服役的要求,采用包埋法对P110钢进行渗铬处理.借助扫描电镜、能谱仪和x射线衍射仪,对渗铬层的表面形貌、显微组织、成分分布和相结构进行了分析和表征,利用电化学测试技术测定P110钢及其渗铬层在CO₂饱和模拟油田采出液中的开路电位、极化曲线和交流阻抗谱.结果表明：渗铬层由Cr₂₃C₆、Cr₇C₃和（Cr,Fe）₇ C₃等相构成,且均匀、连续,与P110钢相比,具有更高的开路电位和电荷转移电阻及更低的电流密度和腐蚀速率.渗铬处理显著提高了P110钢的耐蚀性.     

热喷涂铝涂层在矿井水中的耐蚀性能研究

应用腐蚀失重方法和电化学极化技术研究了热喷涂铝涂层在矿井水环境下的耐腐蚀性能,并与普通碳钢Ｑ２３５进行对比．实验结果表明,在一般中性矿井水中,涂层的自腐蚀电位附近的腐蚀受阴极氧扩散控制,当电位较高时,阳极上有氢析出,阳极反应由此变得复杂;用阴极极化能更好地显示涂层的电化学极化过程．热喷涂铝层具有较高的耐蚀性,实验涂层的预计使用寿命为２０ａ．比较了用失重法和电化学法计算涂层腐蚀速度的结果;分析了在２０～６０℃范围内温度对涂层腐蚀过程的影响     

锌粉热镀锌钢丝的试验研究

本文提出锌粉热镀锌钢丝新工艺,采用新研制的粘镀剂,将锌粉粘附在钢丝表面,加热后使锌粉熔镀到钢丝上。粉镀锌钢丝质量均达到热镀和电镀钢丝的相应标准,镀层质量达到美国ASTM A641M-84的先进水平。工艺稳定,劳动条件优于热镀和电镀法,锌利用率高,能耗低,从而使成本降低,有明显的经济效益和社会效益。并通过金相法和电子探针对粉镀锌钢丝镀层组织和定点成分分析,提出了镀层形成机理和相组成。     

硫脲对Ni-P镀层腐蚀行为的影响

在镀液中添加硫脲,分析了硫脲对Ni-P镀层沉积速度、表面形貌、孔隙率等的影响,并通过极化曲线和交流阻抗测试了硫脲对Ni-P镀层腐蚀性的影响。结果表明,当镀液中添加1 mg/L硫脲时,镀层的沉积速率加快,腐蚀速率增大。这主要是因为镀液添加硫脲后,镀层的孔隙率加大,促进了腐蚀介质渗入到基体表面,增加了腐蚀微电池的数量,形成了大阴极(镀层)-小阳极（基体）腐蚀微电池,使自腐蚀电流密度增大,电荷转移电阻减小。当镀液中添加硫脲质量浓度大于3 mg/L时,镀液被毒化,无法施镀。