沥青混合料油蚀评价方法研究

试验容器、油品用量、油蚀方式及油蚀时长是影响沥青混合料油蚀试验合理性和准确性的4大因素。通过设计试验容器统一试验容器、油品用量、油蚀方式3大因素,根据油蚀试验规律确定24 h为油蚀时长较为合理,对比分析柴油和机油于常温(20℃)、高温(60℃)下沥青混合料的飞散质量损失和油蚀飞散损失结果。结果表明:油蚀飞散损失能更为准确的评价油蚀效应,改进的沥青混合料油蚀试验方法能够更为合理、准确地评价油蚀现象。

沥青混合料的抗油蚀性能

公路上燃油汽车漏油情况时有发生,对路面造成不同程度的污染,影响路面的强度。本文通过室内劈裂强度试 验,考察油污染腐蚀对沥青混合料性能的影响,并且给出抗油蚀评价方法的建议以及改善混合料抗油蚀能力的措施。

沥青玛蹄脂碎石混合料抗油蚀性能试验研究

采用室内性能试验,对5种沥青玛蹄脂碎石(SMA)混合料的抗油蚀性能进行了评价,分析了沥青类型、抗油蚀剂掺量、浸油时间等因素对其力学性能和路用性能的影响,通过扫描电子显微镜(SEM)和傅里叶转换红外光谱(FTIR)研究了沥青油蚀的作用机理.结果表明:发生油蚀破坏后,普通沥青混合料各项性能的下降幅度最大;SBS改性沥青混合料在短时间内具有一定的“油蚀保护”作用,但是经过长时间油蚀后,其保护作用逐渐失效;掺加抗油蚀剂的沥青混合料能够一直保持足够的力学性能和路用性能,其抗油蚀剂最佳掺量为沥青混合料质量的0.4%;浸油后抗油蚀沥青混合料表面呈现薄层状平面结构,沥青膜裹附完整,表现出良好的黏附性和整体性;掺加抗油蚀剂可以有效地避免沥青成分中强极性芳香族化合物的油蚀损失.

沥青油蚀机理研究

提出油蚀度这一评价油品对沥青油蚀效应的指标,设计了试验工具及试验方法,在此基础上,评价在20℃、60℃下柴油对70#基质沥青和PG-82改性沥青的油蚀效应,通过分析其规律,阐述沥青油蚀机理。

油蚀对TLA改性沥青混合料水稳定性的影响

通过制定室内油蚀试验方案,采用浸水马歇尔和冻融劈裂试验,分析了油蚀对TLA改性沥青混合料AC-13C的水稳定性的影响规律.研究结果表明,油蚀对水稳定性的影响与TLA掺量和油蚀时间密切相关,其中,油蚀浸水残留稳定度和油蚀冻融残留强度比随着TLA掺量增加呈现先增后减的单峰变化关系,且峰值出现在TLA掺量为30%左右;同时,初期60 min内油蚀浸水残留稳定度的降幅占总降幅的80%以上.因此,适宜的TLA掺量与及时的除油污处理可有效提高TLA改性沥青路面的抗油蚀水损坏能力.

油蚀对沥青混合料高温性能的影响

公路上燃油汽车漏油情况时有发生,造成沥青路面不同程度的污染,影响沥青路面性能。对沥青混合料试件表面涂刷柴油和机油的方式模拟油蚀过程,采用马歇尔试验及车辙试验,测试并分析了油蚀过程对沥青混合料试件高温性能的影响。结果表明:油蚀过程将显著降低沥青混合料试件的马歇尔稳定度和动稳定度,降幅与油蚀时间成正比;柴油油蚀对沥青混合料稳定度降低的影响大于机油油蚀的影响;与SMA-13混合料相比,AK-13A混合料的抗油蚀能力更低。

油蚀对TLA改性沥青高温性能的影响分析

对TLA改性沥青及基质沥青进行了油蚀试验,并对油蚀后的沥青试样进行了针入度、软化点、当量软化点和粘度等试验,结果表明,油蚀后沥青高温性能显著下降,但随着TLA掺量的增加,试样的高温性能和抗变形能力有所提高。

基于油蚀度的沥青混合料油蚀评价方法研究

基于油蚀度的概念,提出了沥青油蚀度试验方法。根据该方法,定性、定量探讨了高温、常温下基质沥青、改性沥青的油蚀度变化规律以阐释沥青油蚀机理,并进行了油蚀条件下沥青混合料的马歇尔稳定度试验、浸水马歇尔稳定度试验、肯塔堡飞散试验及车辙试验。结果表明:根据油蚀度试验方法所得到的沥青油蚀度试验结果能较好地区分不同沥青的抗油蚀能力,油蚀度越大,抗油蚀能力越差;沥青油蚀机理在于油品与沥青成分上的相似相溶造成沥青粘结料粘结力下降;高温多雨地区,在评价油品对沥青混合料高温稳定性、水稳定性的影响时,车辙试验、肯塔堡飞散试验适应性较强,建议优先选择。文中提出的油蚀度方法和优选的油蚀评价方法能够为油品泄露事故的应急检测、快速诊断提供参考和依据。

计入曲轴油道机油流动的轴承弹流润滑分析

基于轴承弹流润滑分析的Reynolds方程和Greenwood/Tripp接触模型,对一台四冲程汽油机的某连杆轴承及其相邻主轴承进行润滑分析,包括引入Kirchoff准则和Bernoulli方程分析曲轴油道内的机油流动、搭建油道空穴模型,以模拟油道内的空穴现象。结果表明,计入油道内的机油流动对连杆轴承润滑的分析结果产生明显影响,由于计入油道内的机油流动而改变了边界条件,引起连杆轴承最大油膜压力增加,最小油膜厚度减小,端泄油量和最大摩擦损失功率增加。另外,通过曲轴油道内的机油流动分析可得到油道内的油压分布和机油流量,预测油道空穴的发生;因此,引入油道内机油流动分析对油道空穴预测和合理设置连杆轴承边界条件有重要意义。

沥青混合料抗油浸蚀能力分析

以广东地区较常采用的 SMA16和 AK16 A抗滑层混合料类型 ,分析不同改性沥青及沥青改性前后混合料的抗油浸蚀能力 ,并以“油蚀系数”来评价沥青混合料的抗油浸蚀能力 ,油蚀系数越大 。

半柔性铺装技术浅析

半柔性铺装材料是将特殊级配的水泥胶浆灌入多孔母体沥青混合料空隙之中而兼具水泥混凝土 (刚性 )与沥青混合料 (柔性 )双重优点的路面技术 ,具有改善了路面的抗车辙、开裂、油蚀、推移等病害的能力。根据国内外多年的研究经验以及自己的使用论证 。

Corrosion fatigue behavior of epoxy-coated Mg-3Al-1Zn alloy in gear oil

The corrosion fatigue behavior of epoxy-coated Mg-3Al-1Zn alloy in gear oil was investigated. The corrosion and the fracture surfaces after fatigue test were analyzed by scanning electron microscopy(SEM) and the corrosion compositions were measured by energy-dispersive spectrometry(EDS). The fatigue properties and the crack initiation mechanisms of the specimens before and after epoxy coating treatment were discussed. The results indicate that the fatigue limit after epoxy coating treatment in gear oil is higher than that of the uncoated specimens. The epoxy coating is an excellent way to prevent direct contact between the Mg-3Al-1Zn alloy and surrounding environments. The mechanical properties of the epoxy coating layer are lower than that of magnesium alloy, which is the main reason for the fatigue crack initiation on the epoxy coating layer. In addition, the gear oil lubrication could lead to the flaking off of the epoxy-coated layer.

A Study of Lead Corrosion of Diesel Engine Oil

The effect of base oils,sulfur-containing multi-functional additives and dispersants in formulated diesel lubricants on lead corrosion was evaluated by a self-established high temperature corrosion bench test.Test lead coupons were analyzed by XPS to determine the resulting surface chemistry.The results showed a close correlation between the oxidation stability of base oil blend and the lead corrosion of formulated diesel lubricants.The zinc dialkyldithiophosphate(ZDDP)and zinc dialkyldithiocarbamate(ZDDC)have formed different protective films on lead coupon surfaces.A more or less amount of the protective film formed is the main factor affecting the degree of lead corrosion.The glassy zinc phosphates protective film formed by ZDDP is more effective than the zinc sulfides film formed by ZDDC.The interaction between dispersants and ZDDP had a significant impact on lead corrosion.

Effects of Corrosion Inhibitors on Lubrication Performance of Rolling Oil for Copper Foil

The 2,5-bis（ethyldisulfanyl）-l,3,4-thiadiazole （T561）, benzotriazole （BTA）,1-N, N-bis （2-ethylhexyl） aminomethyl-4-methyl-lh-benzotriazole （IRGAMET39） and I-IN, N-bis （2-ethylhexyl） aminomethyl] methyl benzotriazole （TT- LX） have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy （SEM） and energy dispersive spectrometry （EDS） analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.

Effect of Corrosion on the Ship Hull of a Double Hull Very Large Crude Oil Carrier

This study aims to examine and analyze the effect of corrosion wastage on the ship hull of a double hull very large crude oil carrier. To calculate the ultimate bending moment capacity, along with the neutral axis position at the limit state, section modulus, and moment of inertia, the incremental-iterative method is employed. This paper also considered the residual strength checking criteria of ship hull and the ultimate stress behaviors of the representative structural elements. Then, Paik's probabilistic corrosion, which employs two levels of corrosion rate and three different assumptions of coating life time, is applied to assess the corrosion effects. The calculation results obtained through relevant analyses are also presented.

Influence factors on stress corrosion cracking of P 110 tubing steel under CO2 injection well annulus environment

Stress corrosion cracking （SCC） behavior of P 110 tubing steel in simulated C02 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease ofpH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.

The Life Assessment of API 5L Grade B Geothermal Pipeline in Correlation with Corrosion under Insulation

The corrosion under insulation dominates metal loss in the case of API （American Petroleum Institute） 5L Grade B geothermal pipeline, whereas, the other possible corrosion causes, such as stress corrosion and thermal cracking, did not serve a role as critical factors regarding to pipeline degradation during 26-years working operation. Actually, the header pipe diameter 32 inches and 40 inches require priority for inspection due to higher corrosion rate compared to smaller pipe diameters. By simulation method on similar heavy duty service condition in which the working pressure of 15 bars and temperature of 183 ℃, it was proved that corrosion rate will severely occur at corrosion rate more than 10 mpy in the pipe diameters of 20 inches, 32 inches and 40 inches. Further,condensation factor may contribute more significant in the case of corrosion under insulation. Practically, the metal loss at a half initial thickness requires priority for inspection, intensive maintenance or possible partial replacement.

Research on compound plugging removal technology and its application in Xinmu oilfield of Jilin

Most fault-block reservoirs in Xinmu oilfield belong to heterogeneous sandstone in characters which has low permeability, and reservoir pollution is a common phenomenon in this area. Acidizing deplugging in oil wells has become one of the major measures to improve production efficiency in the field. A compound deplug- ging technology in high efficiency low corrosion is developed for this kind of low permeability sandstone reser- voir. On the basis of profoundly understanding of the reservoir＇s physical properties and sensitivity, along with comprehensive analysis of the cause for jams in oil wells, a series of experiments are carried out in order to in- vestigate the dissolution reaction among samples and deplugging inhibitor, sample dissolving speed, formation fluid compatibility, reduction of secondary pollution, etc. Considered reservoir condition in nearby wells the op- timized compositional deplugging liquid formula is selected for this reservoir. It is featured by reducing the de- plugging reaction speed, extending solution for processing radius, preventing secondary damage in dissolution processing, and removing plug pollution effectively. To implement this high efficiency low corrosion deplugging measure based on reservoir condition in the borehole and nearby wells, a relatively better result of deplugging and production increasing is achieved, which enriches the measures to increase production in Xinmu oilfield, and this method can be applied to other similar oiffields for the purpose of maintaining the crude oil production and providing assistant for increasing the production significantly.

Corrosion Resistance of Valve Steels in Combustion Gases from Gasoline and Propane-Butane

The corrosion resistances of widely used X33CrNiMnN23-8, X50CrMnNiNbN21-9, X53CrMnNiN20-8 and X55CrMnNiN20-8 high-alloyed austenite valves steels in combustion engines have been compared. The comparison was performed on the basis of results of kinetic corrosion of the test steels in combustion gases from gasoline with 5% ethanol additive （v/v） and the combustion gases from propane-butane. The corrosion test was performed gravimetrically under thermal shock conditions by heating samples of the test steels from room temperature up to 1,173 K in exhaust gases from a combustion engine, and holding them at this temperature for 2 h and then cooling at room temperature for about 25 min. Then the same thermal shock was repeated and after every 10 to 20 such cycles the mass of the specimens was measured. This experiment simulated the working conditions of a highly thermal loaded exhaust valve in a spark ignited engine. The analysis performed shows that the corrosion resistances of X33CrNiMnN23-8 and X50CrMnNiNbN21-9 valve steels in an environment of combustion gases from propane-butane and in gases from gasoline with 5% ethanol additive （v/v） are comparable, whereas the corrosion resistance of X53CrMnNiN20-8 and X55CrMnNiN20-8 valve steels in an environment of combustion gases from propane-butane is slightly worse than in gases from gasoline with 5% ethanol additive （v/v）.

A Sacrificial Layer Etching Method Applied in Surface Micromachining Using Agitated BHF and Glycerol Solution

A modified buffered-HF solution with NH4 F ： glycerol ： HF（4 ： 2 ： 1）is studied. With the implementation of a heating and agitating mechanism, this method is applied in a sacrificial layer etching scheme that increases the selectivity between silicon dioxide and aluminum. The etching rates of SiO2 and Al as a function of solution temperature are determined. Moreover,the effects of adding glycerol and agitating the etchant are examined and compared with this method. Finally, this method is tested on an actual device, and its efficiency is scrutinized.