影响钨酸盐复合海水缓蚀剂缓蚀性能的因素

采用失重法、电化学法对钨酸盐复合缓蚀剂的缓蚀性能及缓蚀机理进行了研究.结果表明,温度30～60℃、pH值为6～10、海水浓缩倍数在0.5～2.0时,添加复合缓蚀剂及不同杀菌剂对已腐蚀的试片缓蚀率变化幅度不大,均有很好的适应性;钨酸盐复合缓蚀剂主要体现的是抑制阳极反应为主的混合型缓蚀作用,24 h后的缓蚀率比40 min后测得的缓蚀率更高.     

天然海水中钼酸盐复合缓蚀剂对A3钢的缓蚀效果

已有的海水缓蚀剂多局限于模拟环境,在天然海水中的适应性较差.将A3钢浸于添加了钼酸盐复合缓蚀剂的海水中,研究了浸泡时间、缓蚀剂组分投加顺序、海水温度、氯离子浓度、pH值、杀菌剂类型对缓蚀剂缓蚀效果的影响.结果表明:试片在含有钼酸盐复合缓蚀剂的海水中浸泡40 min的阻抗谱直径比浸泡24 h的稍大,在空白海水中浸泡40 min和24 h的阻抗谱直径相差较大,即复合缓蚀剂对浸泡时间有一定的适应性;缓蚀剂组分投加时先加入钼酸盐,试片自腐蚀电位最大,阳极极化曲线斜率变化较明显,该缓蚀剂是以钼酸盐为主剂的复合型缓蚀剂;复合钼酸盐缓蚀剂在海水温度为30～60℃、pH值为6～10内使用,缓蚀率变化较小,对冷却水系统常用的杀菌剂也有良好的适应性,并适用于NaCl质量分数小于8%的海水循环冷却系统.     

羧酸类铜缓蚀剂的制备及性能测试

介绍了新型羧酸类铜缓蚀剂的制备方法,用挂片失重法和测试电化学极化曲线的方法,研究了其对铜在海水中的缓蚀性能,并同BTA的缓蚀性能进行了对比;结果表明,该类缓蚀剂制备工艺简单,具具有比BAT更好的缓蚀性能。     

温度对新型咪唑啉抑制CO2腐蚀的影响

关于温度对油田环境中咪唑啉缓蚀性能影响的研究较少。自制了硫脲基咪唑啉,研究对比了其在358K和298K下对CO2的缓蚀性能。采用失重法测定了该咪唑啉缓蚀剂在358K下对Q235-A钢在饱和CO2盐溶液中的缓蚀率;利用动电位极化曲线、交流阻抗法研究了Q235-A钢在饱和CO2盐溶液中温度对该缓蚀剂缓蚀行为的影响,探讨了吸附膜的形成与衰减规律。结果表明:该缓蚀剂对Q235-A钢的缓蚀作用具有浓度极值,极值浓度为40mg/L;2种温度下,该缓蚀剂都属于抑制阳极过程为主的混合型缓蚀剂,成膜速度较快,24h即可形成致密的吸附膜;低温条件下比高温时成膜更加紧实致密、稳定性好,膜寿命长。     

盐水介质缓蚀剂的合成及性能研究

用正交试验法合成出一种代号为ZJ-1在盐水中使用的缓蚀剂，用失重法分析了缓蚀剂加量、盐水浓度，温度对缓蚀性能的影响，并简单评价了ZJ-1的溶解分散性、与油田工作液处理剂的配伍性。结果表明，该缓蚀剂具有良好的溶解分散性。一定的抗温性和良好的抗盐性，且该缓蚀剂与除氧剂Na2SO3，粘土稳定性FP-1有良好的配伍性，但防垢剂PPS及杀菌剂QA-1会影响其缓蚀效果。     

缓蚀剂在化学抛光液中对铝的缓蚀效果

用失重法阐述了缓蚀剂在化学抛光液中对铝及铝合金的缓蚀效果.实验结果表明,在化学抛光液中,具有协同效应的复合缓蚀剂比单一缓蚀剂有着更加优越的缓蚀性能.     

应用于高矿化度油田回注水的高效杀菌缓蚀剂

西北地区高矿化度油田回注水管道结垢严重,多种细菌滋生,存在严重的垢下腐蚀.为了减少细菌对输水管道的腐蚀,研制出了一种高效杀菌缓蚀剂.通过将杀菌剂双癸基二甲基氯化铵与多种D-氨基酸复配,实现了对附着在垢层中腐生菌、铁细菌和硫酸盐还原菌的杀菌率均超过96％的目标.研究了时间、温度等对复配杀菌剂杀菌率的影响,结果表明:该复配杀菌剂的杀菌率随时间的延长而升高,在12 h后杀菌率接近100％;在40～70 ℃盐溶液中杀菌率均超过97.5％,表现出对温度良好的稳定性.同时,复配的杀菌缓蚀剂由于D-氨基酸的加入也具备了一定的缓蚀能力.因此,该杀菌缓蚀剂还可以作为缓解高矿化度油田回注水水管腐蚀的添加剂使用.     

醋酸乙烯-富马酸酯共聚物降凝剂的合成及其降凝作用

本文研究了醋酸乙烯-富马酸酯共聚物降凝剂的合成机理,生产工艺参数;考察了该降凝剂在150SN基础油中的降凝效果,与T602-HG、T808A、P148降凝剂做了对比试验;并探讨了其降凝机理。     

油田污水处理用复合型阻垢缓蚀剂

油田污水对金属材料有较大的腐蚀性,也容易结垢,使工业设备受损失.为此,复配了3种膦系阻垢缓蚀剂,研究了其在室内模拟油田污水中的性能.利用静态失重法、动态失重法、正交试验法综合评价膦系、无机型阻垢缓蚀剂的协同效应;通过X射线衍射,SEM,电化学等分析方法考察了膦系阻垢缓蚀剂的阻垢、缓蚀性能.结果表明,配制的3种膦系阻垢缓蚀剂具有复合协同效应,能综合提升阻垢缓蚀性能.     

烷基三唑类缓蚀剂的合成及对N80碳钢的缓蚀性能

目前,对引入长链烷基的三唑类缓蚀剂在盐酸中对金属缓蚀性能的研究尚存在着较大的空白。合成并探讨了烷基三唑类缓蚀剂对碳钢的缓蚀作用机理,采用失重法和电化学法测试评价了3种不同碳链长度的三唑类缓蚀剂对N80碳钢在盐酸中的缓蚀性能,采用扫描电镜(SEM)观察了其缓蚀前后的表面形貌。结果表明:3种缓蚀剂均能有效抑制盐酸对N80碳钢的腐蚀,为阴极抑制型缓蚀剂,在N80碳钢表面的吸附服从Langmuir等温吸附模型;在较低温度下,缓蚀剂碳链越长,缓蚀性能越好;缓蚀剂分子中吸附基团的比例随着碳链的增长而降低,随着温度的增加,缓蚀剂分子热运动加剧,吸附能力降低,碳链较短的缓蚀剂高温条件下能达到更高的缓蚀率。     

Corrosion failure analysis of high strength grade super 13Cr-110 tubing string

The main reasons for corrosion failure of super 13Cr-110 tubing and couplings have been proposed based on the analysis techniques of Optical Microscopy (OM), Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) and X-ray Diffraction (XRD). The results show that the composition, structure and mechanical properties of the tubing and the coupling were all in accordance with the corresponding parameter requirements of API Spec 5CT standards. Furthermore, corrosion occurring in the inner wall of joint was caused by the combined impacts of CO₂ corrosion, acid corrosion, erosion corrosion, and crevice corrosion, meanwhile, the synergistic effects of crevice corrosion, and sulfate-reducing bacteria (SRB) corrosion resulted in corrosion occurring in the outer wall of the tubing and the coupling. Finally, to check the quality of the tubing string before well completion, increase torque, install a centralizer, and add bactericide and inhibitor were advised to prevent the types of corrosion failure from taking place.     

Near-infrared spectroscopy for on-line monitoring of lube base oil processes

Near-infrared (NIR) spectroscopy has been utilized for monitoring the pour point of the lube base oil (LBO) process. Using partial least-squares (PLS) regression, necessary spectral features were successfully extracted and correlated to the reference pour-point data. In a preliminary laboratory feasibility study, it was found that PLS calibration performance was largely governed by the accuracy of the reference pour-point analysis. The same NIR spectroscopic methodology was moved to monitor the pour point continuously in an on-line manner. At this time, the NIR spectrometer was calibrated with the existing on-line pour-point analyzer, which was more accurate. In comparison with the on-line pour-point analyzer, NIR spectroscopy provided faster and more repeatable analytical data. With the help of NIR analysis, LBO process variations during product switch can be detected earlier, and necessary process-control strategy can be applied to improve the process efficiency.     

Failure analysis of a leak-off oil pipe from injection valves of an off-shore operating diesel engine

The failure analysis of a four-stroke 3000 kW off-shore operating diesel engine is presented. The failure occurred during engine normal operation period in the leak-off oil pipe from the injection valves, which experienced a fracture through the pipe wall and a diesel engine fire as a result. A detailed analysis of all elements which had an influence on the failure initiation was carried out, namely leak-off oil pipe vibration level, pipe stress level, presence of corrosion pits on the pipe external surface under the zinc coating and engine components temperature distribution in the failure zone. It was found that the crack initiation and propagation of the leak-off oil pipe from injection valves was driven by a fatigue mechanism, which was facilitated by loose pipe supports (excessive pipe vibration) and corrosion pits on the pipe surface that acted as stress concentrators. The contact of leak-off atomized oil due to the pipe through wall fracture with the hot engine exhaust muff (390 °C approximately) caused local fire of the diesel engine.     

新型水溶性缓蚀剂的研究及应用

针对目前油田使用缓蚀剂存在油中溶解度大,缓蚀效果差的问题.采用密闭搅拌法对多种现有缓蚀剂进行了乳化性、水溶性、缓蚀剂效果评价,并在此基础上研制了新型ZYC-1型水溶性缓蚀剂.应用表明,油井及端点投加该缓蚀剂后,在投加量较小的情况下,总铁及腐蚀速率均有明显降低,缓蚀效果显著.     

The Inhibitive Action of Castor Seed Oil Toward the Corrosion of Aluminum in Saline Medium

Corrosion of metal is a costly material science problem which originates from the day of metal discovery. Corrosion inhibitor usage is an effective way of addressing metallic corrosion in aggressive environments but continued usage of synthetic chemicals for inhibiting corrosion is indefensible as a result of toxicity of the chemicals to the environmental ecosystem. Eco-friendly corrosion inhibiting alternatives are therefore needed. In view of this, castor seed oil was evaluated as anti-corrosion protection of aluminum surfaces in saline medium using weight loss and potentiodynamic polarization methods at 304 K. The obtained results show that castor seed oil on aluminum in saline medium decreased the corrosion rate at different concentrations studied. Inhibitor efficiency (IE) of 85.19% at 0.5 g/L and 41.16% at 0.1 g/L castor seed oil was obtained after 48 h of immersion, respectively, which indicates the inhibition efficiency of the inhibitor increased with an increase in concentration of inhibitor at the studied temperature. The presence of castor seed oil as corrosion inhibitor shows increased inhibition efficiency, potential value and polarization resistance with decreased current density. The inhibitor is a mixed-type inhibitor that can control both cathodic and anodic corrosion which obeyed Langmuir adsorption isotherms.     

国内外油气管道腐蚀与防护的研究进展

国内外的石油行业发展中,普遍存在着油气管钢材易被腐蚀而发生事故的现象.对此,综述了影响油气管钢材腐蚀的5种因素,即CO2含量、H2S含量、含砂量、有机酸、温度,在其他条件保持不变的情况下,增加这5种因素中的任何1种,都会加速钢材的腐蚀.同时,还综述了国内外针对油气管材防腐蚀的多种方法,如:在碳钢中加入Cr、V等合金元素,涂覆、浸镀耐腐蚀涂层,使用缓蚀剂,这3种方法均能有效改善石油管材被腐蚀的现象.     

Coatings and hardfacing alloys for corrosion and wear resistance in diesel engines

Abstract

The potential for surface engineering solutions to increase the corrosion and wear resistance of diesel valves is examined with regard to operation in residual fuel oil combustion products. The environment in which the exhaust valve operates is discussed. The corrosion test is used to sort the 27 coating treatments and 16 hardfacing alloys examined. H ardfacing materials showing the greatest potential are also evaluated in hot wear tests. As reference materials, En 52 steel, Nimonic 80A, and Stellite 6 are included. Corrosion tests over the temperature range 500–700°C have shown that the surface treatments can be ranked in terms of their composition and expected metal surface temperature. Good corrosion resistance to residual fuel oil combustion products reflects primarily the content of the alloy, the base metal (Fe, Ni, or Co) being of secondary importance. Refractory metals (Ti, Nb, Ta, Mo, and W) and other minor alloying additions do not significantly alter the corrosion behaviour, unless they are present in large quantities. Hot wear tests (650°C, 80 MN m^?2 contact pressure) of candidate hardfacing alloys have also demonstrated the importance of the Cr content of the alloy. This probably results from the ease of formation of a protective glaze, lowering the coefficient of friction and therefore the wear rate. Additions of refractory metals were beneficial. Since optimum wear resistant alloys contained high levels of Mo and vv: they were poor in terms of corrosion resistance. It is therefore necessary to balance wear resistance against corrosion resistance in the selection of materials for residual fuel oil service. Two coating systems, vacuum plasma sprayed Ni–50Cr and a chromised diffusion treatment appeared to have potential as valve surface treatments for improved corrosion resistance; and two hardfacing alloys, Tristelle TS2 and Colmonoy 8, offered balanced behaviour as seat materials with acceptable wear resistance and improved corrosion performance. These materials have been evaluated in the engine tests of three different diesel engine manufacturers.

MST/3157     

橡胶件在燃油中腐蚀溶胀性的对比

将丁腈、氢化丁腈、氟橡胶分别浸泡在乙醇、柴油、生物柴油中,测量每组样件的直径、质量和硬度值,计算其变化率,并采用扫描电镜对腐蚀溶胀后的橡胶件进行微观形貌结构分析。结合测量数据与扫描分析结果,分析材料间极性的差异对橡胶腐蚀溶胀的影响。结果表明,样件上述各参数变化率与微观形貌变化一致,氟橡胶在柴油中变化率最低,抗腐蚀溶胀效果最佳。     

Strength retention of silicon nitride after long-term oil immersion exposure

Two commercial grade silicon nitride ceramics (Honeywell GS44 and Kyocera SN235) were exposed to an oil ash to evaluate the long-term corrosion/oxidation resistance in a simulated diesel engine environment. The exposure condition was at 850 °C for 1000 h in air. Subsequently, the exposed specimens were tested in flexure for strength degradation at room temperature and 850 °C at stressing rates of 30 MPa/s and 0.003 MPa/s in air, respectively. A similar set of specimens not exposed to the oil ash was also tested in flexure for purpose of comparison. Little change in strength was measured after 1000 h exposure in the oil ash environment. Also, the values of Weibull modulus obtained for all of the exposed silicon nitride materials were similar to those with the unexposed specimens whose strength were obtained under the same conditions. However, both exposed and unexposed GS44 specimens exhibited a low fatigue exponent, suggesting a susceptibility to slow crack growth at test temperature. In addition, detailed SEM/EDAX analyses indicated that no oil ash elements (e.g., Zn, Ca, P, Na, and S) were detected beneath a thin layer in the surface; thus, there were no changes in the chemistry of the secondary phase(s) within the bulk. These elements were detected only in a region about 1–3 μm below the exposed surface, but no apparent changes in microstructure observed. Results of mechanical properties and microstructural characterizations indicated that these candidate silicon nitride materials exhibited excellent corrosion/oxidation resistance in the simulated diesel engine environment and, based on their excellent mechanical strengths, would be ideal candidates for diesel engine exhaust valve applications.     

盐酸清洗腐蚀钢片用缓蚀剂的研制及应用

用盐酸清洗石油化工产品腐蚀试验中样片表面的腐蚀氧化产物时易产生过度酸洗.以盐酸为清洗剂,乌洛托品、苯并三氮唑、OP-10等化学试剂复配缓蚀剂,清洗残渣燃料油腐蚀试验后钢片表面的腐蚀产物,并用失重法和金相显微镜表征清洗效果.试验表明复配的缓蚀剂缓蚀效果良好,该缓蚀剂可以使盐酸在4 min内有效清除钢片表面的腐蚀产物而不伤害钢片基体,有效提高了腐蚀试验的精密度.