门窗五金件镀层腐蚀失效分析和解决

针对某门窗五金组合件表面镀层达不到中性盐雾试验要求的问题,通过分析故障特征和试验验证,得出主要原因为镀Zn–Fe合金的锌合金固定座与镀Zn–Ni合金的Q235钢铆接件之间发生了电偶腐蚀,提出改用1Cr17钢制作铆接件以及电镀后用苯并三氮唑封闭的解决措施。     

化学镀Ni-P合金镀层在低温模拟海水中的腐蚀性能

为了改善Q235钢在低温海水中的耐蚀性,在Q235钢表面化学镀Ni-P合金镀层。采用显微镜观察了镀层的表面形貌,采用X射线衍射仪分析了镀层的结构,并通过浸泡试验、极化曲线和电化学阻抗等方法考察了Q235钢和镀层在5℃的模拟海水中的耐蚀性。结果表明:化学镀Ni-P合金镀层表面的胞状物分布较为均匀,镀层为非晶态结构,镀层在低温海水中的腐蚀速率约为Q235钢的1/5。这主要与该镀层在海水中能够发生钝化及镀层表面较为致密有关。     

镍磷化学镀层在北方重工业城市雪水中的耐蚀性

为了改善Q235钢在空气污染较为严重的环境中的耐蚀性,以北方重工业城市之一的抚顺望花区的雪水为腐蚀溶液,考察了化学镀镍层在该介质中的耐蚀行为。采用金相显微镜观察了镍磷镀层的表面形貌,通过冷冻-加热循环试验考察了镀层的结合力,借助动电位极化、电化学阻抗谱等方法评价了镀层在雪水中的耐蚀性,测试和观察了浸泡实验的腐蚀速率和表面形貌。结果表明,Ni-P镀层可在Q235钢表面均匀沉积且较为致密,与基体之间有良好的结合力。镀层的自腐蚀电流密度较Q235钢低,电荷转移电阻更大,腐蚀速率是Q235钢的1/3～1/2。Ni-P镀层明显改善了Q235钢在污染较为严重的雪水中的耐蚀性,可作为Q235钢腐蚀防护的一种措施。     

液压活塞杆上电镀铁镍钨和镍钨磷合金的耐磨和耐蚀性能比较

在45钢表面电镀了Fe–Ni–W和Ni–W–P合金。对比了两种钨合金镀层热处理后的显微硬度、元素组成和结晶情况,通过磨擦磨损试验、中性盐雾试验和浸泡腐蚀试验比较了它们的耐磨和耐蚀性能。Fe–Ni–W和Ni–W–P合金镀层均光亮、平滑,晶粒尺寸均在10~40 nm范围内,摩擦因数分别为0.086 1和0.094 4。Ni–W–P合金镀层的耐蚀性优于Fe–Ni–W合金镀层,经中性盐雾试验、5%盐酸浸泡和5% NaOH溶液浸泡96 h后依旧光亮,没有锈蚀点。     

Ni-W-Fe-P四元合金镀层在酸碱盐溶液中的腐蚀行为

在Ni-W-P合金镀液中加入硫酸亚铁,并通过适当的工艺在Q235钢表面制备了Ni-W-FeP四元合金镀层。采用扫描电子显微镜观察了镀层的表面形貌,通过能谱仪测试了镀层中各元素的质量分数,通过X射线衍射仪分析了镀层的结构,并借助极化曲线和交流阻抗曲线方法考察了镀层和Q235钢在体积分数为5%的H2SO4溶液、质量分数为5%的NaOH溶液和质量分数为3.5%的NaCl溶液中的腐蚀行为。结果表明:Ni-W-Fe-P合金镀层为非晶态结构,表面较为均匀,W和Fe的质量分数分别约为2.71%和1.56%。在上述三种腐蚀介质中,镀层的耐蚀性远优于Q235钢的,主要是镀层在酸、碱、盐介质中表面形成钝化膜所致。     

酸性氯化物体系电镀锌铁合金及镀后处理

以30CrMnSiA钢作为基材,先采用酸性氯化物体系电镀锌铁合金,再进行磷化或六价铬钝化.对比了Zn–Fe合金镀层及其磷化试样和钝化试样的外观、表面形貌、耐蚀性和电泳漆膜附着力.结果表明,本工艺所得的锌铁合金镀层更适合磷化后处理.     

模拟工业大气环境中碳钢和耐候钢的腐蚀行为研究

用Na HSO3溶液进行模拟工业大气环境的加速腐蚀试验,研究Q235钢和耐候钢在加速腐蚀试验中的腐蚀情况,通过腐蚀质量损失法对试样的腐蚀速率进行分析,得到Q235钢的腐蚀速率高于耐候钢。采用X-射线衍射对腐蚀产物的成分进行分析,Q235钢和耐候钢的主要腐蚀产物均为Fe2O3、Fe SO4、α-Fe OOH和γ-Fe OOH。电化学测试对腐蚀过程进行分析,耐候钢的耐蚀性更好。表明Q235钢和耐候钢的锈层都有明显的保护作用,耐候钢的耐腐蚀性优于Q235钢。     

电镀铝-锰合金的耐人工汗液腐蚀性能

为解决可穿戴设备中镍镀层受到汗液腐蚀而产生镍释放的问题,提出以Al–Mn合金镀层替代镍镀层。采用扫描电镜(SEM)和能谱仪(EDS)分析了Al–Mn合金镀层的微观形貌、成分,测试了它的表面粗糙度、光泽和努氏硬度,通过静态浸泡腐蚀试验和动电位极化曲线测量研究了Al–Mn合金镀层在人工汗液中的耐蚀性。结果表明:电沉积所得Al–Mn合金镀层镜面光亮、平整、致密,与基体结合良好,努氏硬度高于光亮镍镀层。Al–Mn合金镀层在人工汗液中发生全面的均匀腐蚀,耐蚀性为2级。Al–Mn合金镀层在人工汗液中的腐蚀电流密度与光亮镍镀层相近,但腐蚀电位更负,对腐蚀电位较负的基体起牺牲阳极保护作用,可以替代镍镀层用于汗液腐蚀的环境中。     

湿法超声机械镀锌–铝层的性能研究

以Q235钢片为基体,采用湿法超声机械镀制备Zn–Al复合镀层。用扫描电子显微镜及其配备的能谱仪分析了锌–铝复合镀层的表面形貌、断面形貌和元素组成,并用测厚仪、贴滤纸法和划格试验分别对镀层的厚度、孔隙率和结合力进行表征。结果表明,湿法超声机械镀Zn–Al复合镀层是由锌粉和铝粉颗粒相互镶嵌、填充所形成的致密堆积体,表面均匀、平整,与基体的结合强度高。镀层主要由锌、铝、锡和铁组成,铝的质量分数低于施镀前混合粉体中铝粉的质量分数。在考虑施镀过程中金属粉的损耗后,所得Zn–Al镀层的厚度满足预定的厚度(30μm)要求。     

化学镀镍-磷镀层在氢氟酸中的耐蚀性

为了改善Q 235钢在氢氟酸中的耐蚀性,采用化学镀技术在其表面制备了镍-磷镀层。采用金相显微镜对镍-磷镀层的表面形貌进行了观察,通过浸泡和电化学等方法考察了Q 235钢和镍-磷镀层在氢氟酸中的耐蚀性。结果表明:所得镍-磷镀层光滑、致密、平整,在氢氟酸中表现出较低的自腐蚀电流密度和较大的电荷转移电阻,可明显降低Q 235钢在氢氟酸中的腐蚀速率。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997