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硫铵加热器是硫胺生产的重要设备之一,加热器发生腐蚀引起泄漏事故,严重制约生产,文中对其腐蚀影响因素进行了探讨,并探寻对策。 相似文献
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腐蚀通常是无法挽救的刀具热处理缺陷之一。本文所指腐蚀是刀具表面与某些物质作用使表面完整性遭到破坏,形成条状、针孔状、片状剥落的凹坑。腐蚀增加了表面粗糙值,影响外观质量,若发生在切削部位会影响使用寿命,或因表面粗糙度达不到技术要求而报废。目前高速钢刀具热处理加热、冷却、回火各工序通常全部用盐浴炉,表面清理采取热水清洗、酸洗、喷砂等方法,各类腐蚀时有发生。分析腐蚀产生的原因并采取相应对策防止腐蚀是提高刀具外观质量,延长刀具使用寿命和减少废品的重要课题。常见的腐蚀有以下几种: 相似文献
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本文就加工哈萨克斯坦原油(以下简称“哈油)引起泵的轴密封腐蚀破坏问题进行探讨,调查了轴封腐蚀破坏的情况,找到了破坏的原因,并从用材和结构上提出了相应对策。 相似文献
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从断口宏观特征、材质、断口电镜形貌以及微观组织等方面对发生断裂的氢气预热器连接螺栓进行了分析,结果表明,螺栓断口腐蚀产物为单纯的FeS晶粒。根据高温硫腐蚀机理分析,确定该连接螺栓的断裂是一起典型的高温硫环境下的应力腐蚀开裂失效案例,主要是由于工作介质中含有硫化氢或者硫蒸汽所致。建议提高材料等级,采用0Cr18Ni10Ti不锈钢螺栓,以解决腐蚀问题。 相似文献
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随着我国经济的持续高速发展,各种能源的需求也在不断增长。随着各类石油的长输管线的不断扩建,管线的防腐问题也成了施工中的一个难题,亟待解决,如果不做好石油化工管道的防腐工作,很可能会导致石油化工产品泄漏,导致大量的石油资源被浪费,给人民的生产和生活带来很大的影响。因此,必须对原油管线和储罐进行腐蚀分析,采取相应的防腐蚀保护措施,减少原油管线和储罐的腐蚀,从而保证原油的运输和贮存的安全性。油田集输管线发生腐蚀的原因很多,应针对不同的腐蚀条件,采取有针对性的防腐蚀措施,以减少腐蚀,还需要在原有的防腐蚀技术上对石油化工管道防腐蚀技术进行一定的改进。因此,本文就油田集输管线的腐蚀和防腐蚀技术进行了论述,以期能对我国石油化工工业的发展有所帮助。 相似文献
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柴油中含硫化合物类型分布及变化规律 总被引:2,自引:0,他引:2
采用气相色谱法-硫化学发光检测器研究了几种不同直馏柴油中含硫化合物的类型分布,和直馏柴油加氢脱硫过程中各种含硫化合物类型的变化规律,为加氢脱硫催化剂和工艺研究提供了依据。 相似文献
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A radioactive tracer, sulfur-35, synthesized into zinc dialkyl dithiophosphate molecules, was used to study the EP film formed on cast iron cams and tappets run in motor oils containing this additive. The sulfur content of static films increased with immersion time and temperature, and the presence of phosphate-coated metal surfaces. The bound sulfur of films formed during dynamic tests increased with running time, load, and with the use of phosphate-coated surfaces. These conditions also influenced the ratio of Zn:P:S contained in both static and dynamic films. Zinc, and particularly phosphorus, in the films increased more rapidly than the sulfur with increased temperature and/or pressure. The dynamic films are not easily worn off by running in nonadditive oil. The mechanism of action of zinc dithiophosphates appears to be related to chemical reactions of additive decomposition products with the metal surfaces to form tightly-bound solid films which reduce damage under extreme pressure conditions. Radioactive counting and X-ray spectroscopy were used to obtain the amount of sulfur and zinc on tappets. Densitometer traces of the autoradiographs were utilized to determine the distribution of the sulfur on cam and tappet surfaces. 相似文献
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A study was undertaken to investigate the effects of the EP additives during tribological tests using a CBN tool against steel. Ester oil with and without sulfur additive were used as lubricants in a tribometer. Tribochemical interactions between the S additive and steel have been investigated under boundary lubrication conditions by SEM and EDX analysis. The relative abundance of different elements on the surface of the CBN tools, which are present in the workpiece material such as Fe (iron) and Cr (chromium), suggests that adhesion occurred when the ester oil without sulfur additive was tested. Tribochemical interactions between the additive and the steel could be observed when using the ester oil containing the sulfur additive. These interactions contribute to the formation of a uniform layer on the CBN tool. This layer is composed by S (sulfur), Fe, and O (oxygen). The presence of these elements indicate that FeO (iron oxide) and FeS (iron sulfide) were formed. 相似文献
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利用TXS-Ⅱ微量硫分析仪测定褐煤低温干馏气中含硫化合物过程中存在以下问题:(1)高浓度的H2S和COS经多次稀释会引起分析误差;(2)低浓度有机硫受到高浓度H2S和COS的严重干扰,无法分离检出;(3)科研小试中产气量少,无法满足测定所需的进样量。为了解决上述问题,对TXS-Ⅱ微量硫分析仪的进样系统进行了改造,在原有的六通阀进样器与色谱柱之间串联了一个微量填充柱进样器。改造后,进气量只需要0.1~1000μL,可直接测定H2S和COS的含量,并优化了测定操作条件。改造后的仪器能快速简便地测定褐煤低温干馏气中高浓度H2S和COS及低浓度有机硫含量,稳定性及精密度良好。 相似文献
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Hwanam Kim Yongha Sung Kilsung Jung Byunchul Choi Myung Taeck Lim 《Journal of Mechanical Science and Technology》2008,22(9):1793-1799
Particulate matters (PM) from diesel combustion comprise the major portion of harmful components of air in urban areas. In
this study, the effects of DOC and/or CDPF on the size distributions and catalytic reactions of these nano-sized particles
were investigated to clarify the exhaust mechanism and to minimize the emission of the nano-sized PM. Parameters of interest
in the investigation included sulfur content of the fuels used, air-fuel equivalence ratio, fuel injection pressure, and the
engine speed. The number concentration of the particles in diluted exhaust gas was measured by a SMPS in the diametric range
of 10–385 nm. The number of nanometer-sized particles increased when the engine was operated at high equivalence ratio with
diesel fuel that contained 500 ppm of sulfur. As the sulfur concentration in the fuel increased, the number of the particles
smaller than 30 nm increased upon passing DOC and CDPF in the exhaust system of the common-rail diesel engine. 相似文献
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表面活性元素硫对焊接熔池流动方式和深宽比的影响 总被引:3,自引:1,他引:2
建立了三维移动热源作用下焊接熔池的数学模型,模拟了表面活性元素S在不同质量分数作用下的熔池中的速度场和温度场。结果表明,S元素显著地影响了熔池中的流动方式,熔池深宽比随S质量分数的增加而迅速增大,当S质量分数超过80×10-6时,深宽比趋于一定值。S质量分数小于120×10-6时,熔池表面温度高于正表面张力温度系数发生的温度范围,正、负表面张力温度系数同时存在,温度梯度在最大表面张力处最大;当S质量分数超过120×10-6时,正表面张力温度系数控制着熔池中的流体流动,液体金属从熔池边缘流向熔池中心;随着S质量分数的增加,在熔池中出现数目、大小、方向和位置不同的涡流,当涡流的方向为由熔池边缘流向熔池中心时,涡流有效地把电弧能带到熔池底部,产生较大的熔深。 相似文献