硫酸介质中铸造奥氏体不锈钢的腐蚀磨损行为

研究了几种铸造奥氏体不锈钢在含有Ｃｌ－的硫酸介质中的点蚀规律,测定了腐蚀磨损率、摩擦因数和表面钝化膜破坏后的修复时间。实验结果表明,高铬、镍、铜不锈钢有较高的耐蚀性,但其腐蚀磨损失重却高于一般的１８－８型不锈钢     

Microbiologically Induced Corrosion Action on Al-6Mg-Zr and Al-6Mg-Zr-Sc

The corrosion behaviors of Al-6Mg-Zr and Al-6Mg-Zr-Sc in sulfate-reducing bacteria（SRB） solution in the anaerobic environment were studied by electrochemical, microbiology and surface analysis methods. It is found that the oxide film is more compact resulting in the open circuit potential shifting about 100 mV positively due to the addition of Sc. On the other hand, it is demonstrated that pitting sensitivity of Al-6Mg-Zr-Sc alloy in the SRB solution is decreased and its microbiologically influenced corrosion resistance is improved.     

Study of Microbiologicaily Induced Corrosion Action on Al-6Mg-Zr and Al-6Mg-Zr-Sc

The corrosion behaviors of Al-6Mg-Zr and Al-6Mg-Zr-Sc in the sulfate-reducing bacteria （SRB） solution in anaerobic environment were studied using electrochemical, microbiological, and surface analysis methods. It was found that the oxide film was more compact owing to the addition of Sc resulting in the open circuit potential shifting by about 100mV positively. On the other hand, it was seen that the pitting sensitivity of Al-6Mg-Zr-Sc alloy in SRB solution decreased and its microbiologically influenced corrosion resistance was improved. Pitting corrosion occurring on the surface of the two alloys under the comprehensive action of the metabolism of SRB was observed by SEM. It was obtained by EDS that the corrosion degree increased with time and corrosion was furthered by deposition of the product.     

钛表面钛钯合金层耐蚀性能及耐蚀机理研究

采用磁控溅射沉积钯膜层+热扩散技术在工业纯钛表面制备Ti-Pd合金层,研究了Ti-Pd合金层的耐蚀性能,用重量法评价了合金层的腐蚀速率,分析了不同样品经腐蚀后的表面形貌和成分。结果表明:Ti-Pd合金层在37%(质量分数,下同) HCl溶液和80%H_2SO_4溶液中的腐蚀速率比纯钛降低了2个数量级。Ti-Pd合金层经37%HCl腐蚀后,表面含有Ti、Pd、O元素,表面有微小的点蚀坑。Ti-Pd合金层经80%H_2SO_4腐蚀后,表面含有Ti、Pd、S、O元素,表面有亚微米级的点蚀坑。提出了Ti-Pd合金层的耐蚀机理:微量的Pd和Ti O2组成的钝化膜使表面腐蚀电位提高,产生耐蚀效果。     

439超纯铁素体不锈钢耐蚀性评价

通过盐雾试验、电化学试验和FeCl3点腐蚀试验,并结合扫描电镜,对比研究了439超纯铁素体不锈钢和430普通铁素体不锈钢的耐腐蚀性能。结果表明,碳、氮间隙元素极低的439超纯铁素体不锈钢耐点蚀性能明显优于430普通铁素体不锈钢,虽然430钝化膜修复能力较强,但点腐蚀速率也较快;430不锈钢具有严重的晶间腐蚀敏感性,同样,430普通不锈钢在干湿加速盐雾试验中发生了严重腐蚀,439超纯铁素体不锈钢在上述腐蚀试验中均表现出轻微的腐蚀。可见在430普通不锈钢基础上降低碳、氮间隙元素含量,同时加入钛稳定化元素,使其耐腐蚀性能大幅提高。     

The Enhanced Even and Pitting Corrosion Resistances of Bulk Nanocrystalline Steel in HCl Solution

We studied the corrosion properties of bulk nanocrystalline 304 stainless steel (BN‐SS304) produced by severe rolling technique and conventional polycrystalline 304 stainless steel (CP‐SS304) with immersion test, X‐ray photoelectron spectroscopy, ultra‐violet photoelectron spectroscopy, inductively coupled plasma emission spectrometer, and scanning electron microscope. Immersion test was carried out in 0.5 mol L^?1 HCl solution for 30 days immersion interval at room temperature. It is well known that the pitting corrosion of stainless steel could be inevitable in solution containing Cl^?. However, BN‐SS304 can scarcely suffer from pitting corrosion with the compact oxide film on its corrosion surface and less corrosion rate in comparison with CP‐SS304. The less corrosion rate of BN‐SS304 was attributed to the stronger O₂ adsorption and compact oxide film on its corrosion surface, its less weight of 4s–4s valence electrons and its larger work function in comparison with CP‐SS304. The improved pitting corrosion resistance of BN‐SS304 resulted from the compact oxide film, weaker Cl^? adsorption and less Cl^? chemical activity on its corrosion surface.     

Ce和W对444铁素体不锈钢耐点蚀性的影响

采用浸泡失重法和电化学方法研究Ce和W对铁素体不锈钢在含Cl-溶液中耐点蚀性能的影响,并通过恒电位极化法测定不同Ce和W含量的铁素体不锈钢临界点蚀温度(CPT)。结果表明,W和Ce都可显著抑制铁素体不锈钢在FeCl₃溶液中的腐蚀溶解,且含W的不锈钢蚀坑坑底有W元素富集。Ce和W的添加提高了不锈钢在5%NaCl溶液中的临界点蚀温度,并且当W的质量分数达到1%时,可以显著增强蚀坑的再钝化能力。添加Ce和W可提高不锈钢的点蚀电位,降低腐蚀电流密度,提高不锈钢的耐点蚀性能。不同成分的铁素体不锈钢在中性氯溶液中都表现出稳定的钝态,而Ce和W的添加可以提高钝化膜的稳定性,扩大钝化区范围。     

Study on pitting process of 316L stainless steel by means of staircase potential electrochemical impedance spectroscopy

Pitting corrosion of 316L stainless steel in NaC1 solution was investigated by means of staircase potential electrochemical impedance spectroscopy (SPEIS).The investigation focused on the transition of stainless steel from the passive state to pitting corrosion.Based on the evolution of electrical parameters of the equivalent electrical circuit,it is suggested that the most probable mechanism of pit creation is the film breaking model.The result demonstrates that staircase potential electrochemical impedance spectroscopy is an effective method for the investigation of pitting corrosion.     

2507双相不锈钢在SO2污染模拟海水中的腐蚀行为

采用开路电位、电化学阻抗谱(EIS)、Mott-Schottky曲线和浸泡腐蚀实验研究了2507双相不锈钢在含不同浓度(0,0.001和0.01 mol·L-1)NaHSO₃模拟海水中的腐蚀行为. 研究表明:开路电位随NaHSO₃浓度的增加而负移,腐蚀倾向增大;电荷转移电阻R_t随浓度的增加而减小,耐蚀性降低;2507不锈钢的腐蚀形态为局部腐蚀,点蚀程度随浓度升高有所加剧,腐蚀速率随浓度的增加而增大;Mott-Schottky曲线和成膜后电化学阻抗谱测试表明,NaHSO₃的加入增加了2507不锈钢表面钝化膜的点缺陷浓度,降低了钝化膜的稳定性,电荷转移阻力减小,腐蚀更容易发生. 这可能归因于NaHSO₃的加入增加了模拟海水的酸度,并随NaHSO₃浓度的增加促进了不锈钢表面钝化膜的破坏.      

Effect of C Fraction on Corrosion Properties of High Interstitial Alloyed Stainless Steels

The effects of carbon fraction on various corrosion properties of Fe18Cr10MnNC alloys were investigated. The alloys contained 0.6?wt pct of nitrogen and carbon, and the carbon fraction varied from 0.03 to 0.47. With increasing the carbon fraction, corrosion potential raised, critical dissolution rate decreased, and pitting potential increased. The high carbon fraction was responsible for high resistance against intergranular corrosion of the alloys aged at 1123?K (850?°C) for 100?seconds. But after aging at 1123?K (850?°C) for 600?seconds, the intergranular corrosion accelerated with increasing the carbon fraction.     

时效对Al?2Li二元合金钝化膜耐蚀性及结构的影响

Al?Li合金具有低密度、高强韧性和低的腐蚀疲劳扩展速率的优点,在航空领域有着广泛应用。Al₃Li（δ′）相是Al?Li合金中主要强化相之一,因含有活性元素Li对该合金的腐蚀行为产生显著影响。为明确δ′相在Al?Li合金电化学腐蚀中的作用,真空熔炼制备Al?2Li二元合金,固溶后进行180 ℃等温时效,用X射线衍射（XRD）检测合金的相组成。在质量分数为3.5% 的NaCl水溶液中,用动电位极化的方法测量了该合金的极化曲线。?0.85 V vs SCE钝化电位下形成钝化膜后,用电化学阻抗（EIS）检验钝化膜的耐蚀性;用恒电位阳极极化和Mott?Schottky（M?S）曲线对该合金钝化膜的结构进行分析。结果表明,Al?2Li合金的自腐蚀电位随时效时间增加先正移后负移;固溶和时效合金钝化膜的EIS都由两个容抗弧组成,时效未改变钝化膜的腐蚀机制;钝化膜耐蚀性由高到低的顺序为:时效20 h>固溶>时效40 h>时效1 h,且耐蚀性与其致密性及膜内的载流子密度有关。      

碳含量和组织类型对低合金钢耐蚀性的影响

 研究了碳含量不同和显微组织不同的低合金钢的耐腐蚀性能和腐蚀行为,并和商业耐候钢09CuPCrNi做了相应的比较。在碳含量比较低的情况下,组织类型对试验钢的耐蚀性影响不大;碳含量比较高时,单相贝氏体钢的耐蚀性优于由铁素体、渗碳体(珠光体)等构成的复相组织钢。轧后水冷时,不同碳含量的钢耐蚀性差别不大;轧后空冷时,碳含量低的钢的耐蚀性优于碳含量较高的钢。用扫描电镜对锈层进行观察,可以看出耐蚀性较好的试样在腐蚀后期形成了较致密的内锈层。碳的质量分数分别为0.03%和0.1%的钢水冷后的平均腐蚀速率相差很小,但从微观角度看其点蚀发展趋势不同。加速腐蚀5个周期后,w(C)为003%的水冷钢中蚀坑尺寸不再增加,而w(C)为01%的钢中蚀坑尺寸仍有增加趋势。     

高Ta钛合金在沸腾硝酸中的腐蚀行为

对高Ta含量钛合金Ti-32Ta在8 mol/L沸腾硝酸溶液中进行了全浸腐蚀实验,研究了Ti-32Ta合金在沸腾硝酸中的腐蚀行为。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线衍射光电子能谱(XPS)等分析方法对钛合金腐蚀表面的钝化膜进行了成分、组织结构及合金价态分析。结果表明:Ti-32Ta合金在沸腾硝酸溶液中呈现均匀腐蚀行为,在介质中通入一定流量的新鲜空气对合金稳定腐蚀阶段的腐蚀速率影响不大。与Ti-6Ta合金相比,Ti-32Ta合金腐蚀后形成的钝化膜更薄更致密,耐蚀性能更好。两种合金腐蚀钝化膜中Ti和Ta的价态组成相同,Ti-32Ta合金腐蚀表面Ta及Ta2O5的含量高于Ti-6Ta合金腐蚀表面。     

Morphological Changes During Annealing of Electrodeposited Ni-Cr Coating on Steel and Their Effect on Corrosion in 3% of NaCl Solution

 Steel containing carbon of 02% was coated with Ni and Cr through electrodeposition, and subsequently annealed at 400 and 600 ℃ for 5 min, 30 min, 1 h and 2 h. During annealing at 400 ℃, the formation and growth of oxides occurred in the form of petals along with voids, cracks and porosities. However, at 600 ℃, the nucleation and growth of chromium oxide whiskers produced a surface almost free from crack, porosity and void for 1 h and 2 h of holding. In accordance with the surface morphology, the bare steel, as-deposited steel, all specimens deposited and annealed at 400 ℃, and specimens deposited and annealed at 600 ℃ for 5 and 30 min exhibited continuous corrosion in 3% of NaCl solution. However, the specimens deposited and annealed at 600 ℃ for 1 and 2 h exhibited an improved corrosion resistance in 3% of NaCl solution with high pitting potential due to presence of a dense passive oxide film almost free from voids at the surface.     

Corrosion Behavior of Nitrogen Containing Hot Rolled 304LN in Nitric Acid Medium

The corrosion behaviour of 304LN stainless steels containing three different nitrogen content (0.132, 0.193, 0.406 wt% N) was investigated by potentiodynamic anodic polarization technique, in 1, 4, 6 M nitric acid and simulated high level waste (HLW) medium. The results showed that all three alloys exhibited good corrosion resistance in nitric acid and simulated HLW and the corrosion properties were found to be similar. Owing to the spontaneous formation of the protective chromium oxide passive film in nitric acid and simulated HLW, increasing the nitrogen content of the alloy did not indicate any discernable effect on the corrosion resistance in both media. It was also found that the oxidizing ions present in simulated HLW did not deteriorate the passive film stability of the nitrogen containing alloys. In chloride medium, the highest nitrogen content 304LN stainless steel showed a profound increase in pitting corrosion resistance when compared to the lower nitrogen content alloy. Optical and scanning electron microscopy was carried out to obtain information about the microstructure. The results of the investigation are discussed in the paper.     

厚规格X70管线钢焊接接头盐雾腐蚀行为

通过金相显微镜、扫描电镜对厚规格X70管线钢焊接接头进行中性盐雾试验(NSS试验)腐蚀产物形貌进行观察,采用EDS、XRD分别对腐蚀产物进行面扫描和物相分析。结果表明,盐雾腐蚀过程先发生点蚀,点蚀逐步发展成全面腐蚀。Cl-引起点蚀,点蚀导致裂纹的产生。腐蚀产物成分均匀,主要由铁的氧化物、氯化物和氢氧化物组成。腐蚀速率随着腐蚀时间的延长变缓慢,腐蚀过程中Cl-易穿过外层疏松的腐蚀产物与基体发生反应,而最内层致密的腐蚀产物膜对腐蚀介质的进一步扩散起到阻挡作用,减缓了反应速率提高了耐蚀性。     

Inhibition Performance of Enhanced-Mo Inhibitor for Carbon Steel in 55% LiBr Solution

The inhibition performance of enhanced-Mo inhibitor for carbon steel in 55% LiBr solution was measured by means of chemical immersion,electrochemical measurements,and physical detection technologies.Results indicated that enhanced-Mo inhibitor showed excellent inhibition performance of carbon steel in 55% LiBr solution,especially at high temperature.With increasing the temperature of solution from 160 ℃ to 240 ℃,the corrosion rates of carbon steel increased from 17.67 μm/a to 33.07 μm/a.Enhanced-Mo inhibitor might improve the anodic polarization performance of carbon steel and widen the passive potential region of carbon steel in 55% LiBr solution.Enhanced-Mo inhibitor belongs to anodic inhibitor.In 55% LiBr solution,the relationship between corrosion current density icorr and corrosion potential Ecorr of carbon steel accorded with the equation lgicorr=-2.66-3.54Ecorr,and the value of cathodic Tafel constant βc for the H2 reaction was 282 mVSCE.When 55% LiBr solution contained enhanced-Mo inhibitor,a passive film comprising Fe3O4 and MoO2 was formed on the carbon steel surface by electrochemical reactions.The corrosion of carbon steel might be retarded by this protective film,and the anticorrosion performance of carbon steel in 55% LiBr solution might be improved by enhanced-Mo inhibitor.     

Pitting Corrosion Behavior of Stainless Steel 304 in Carbon Dioxide Environments

The pitting corrosion behavior of stainless steel (SS) 304 in aqueous CO2-H2S-CI-environment was investigated by potentiodynamic cyclic anodic polarization and electron probemicroanalysis (EPMA). The experimental results show that the pitting corrosion susceptivityof SS 304 increases with the increase of temperature. Chlorine ion is the prerequisite for pittingcorrosion of SS 304 in H2S-CO2 environments. There is a linear relatiotxship between the pittingcorrosion potential (Eb-100) and chlorine ion concentration, and Eb-00 becomes noble with in-creasing pH value of the solution with or without H2S. pH value has little effect on the protec-tion potential with the presence of Hz S. H2S increases strongly the pitting corrosion susceptivi-ty and deteriorates the pitting corrosion resistance of SS 304 in CO2 environments. The obser-vations by EPMA show that SS 304 in CO2-saturated NaCI solution (3%) with H2S sufferspitting corrosion accompanied with intergranular corrosion.     

钛合金在HC1-FeC12溶液体系中的腐蚀研究

研究了钛合金在HC1-FeC12溶液体系中的腐蚀行为.研究表明,钛合金在该溶液中的耐蚀性优良,且价格相对较低的Ti-Mo-Ni合金明显优于较昂贵的Ti-Pd合金.同时发现,溶液中的Fe2+对钛合金具有较好的缓蚀作用.     

晶粒细化对Cu-40Ni合金在酸性含Cl-介质中耐蚀性能的影响

采用电弧熔炼（CA）和机械合金化（MA）通过热压烧结工艺制备了晶粒尺寸差别较大的Cu-40Ni合金，借助于PARM273A和M5210电化学综合测量仪，利用动电位扫描法和交流阻抗技术对比研究了上述合金在酸性含Cl^-介质中的腐蚀电化学性能以及腐蚀机制。结果表明：两种合金的腐蚀电位随时间逐渐稳定，在中性Na2SO4溶液中加入H2SO4和NaCl后，两种合金的自腐蚀电位负移；晶粒细化后，两种合金的自腐蚀电位则正移。两种合金在中性及酸性含Cl^-介质中均存在钝化现象，但在酸性含Cl^-介质中钝化区间很短，钝化能力较弱。两种合金的交流阻抗谱均由单容抗弧组成，反应由电化学过程控制。晶粒细化后，合金中存在大量晶界，参与腐蚀反应的活性原子数增加，促使MACu40Ni合金的腐蚀速度高于CACu-40Ni合金。