聚丙烯在衣康酸介质中的腐蚀行为

采用静态腐蚀试验考察试样浸泡前后的重量变化,外观变化,机械性能(硬度和冲击强度)变化以及结构的变化,研究了聚丙烯塑料在衣康酸水溶液中的腐蚀行为。结果表明,聚丙烯在衣康酸中的腐蚀主要包括介质的扩散渗透、助剂溶出和聚丙烯树脂的氧化,介质组成和温度有显著影响。经衣康酸介质浸蚀后,聚丙烯的硬度变化不大,但冲击强度有所下降。根据重量、外观及性能的情况,认为聚丙烯塑料在衣康酸介质中的耐腐蚀性良好。     

腐蚀监控技术在炼油装置中的应用

随着原油品质的下降,在炼油过程中造成的腐蚀问题,受到广泛重视,腐蚀监控技术得到快速发展.炼油装置中的均匀腐蚀情况可以通过电阻探针监控法和电感探针监控法来进行监控,点腐蚀情况可以通过线性极化探针监测法和电化学噪声监控技术来进行监控,应力腐蚀情况可以通过氢通量测量技术和线性极化探针监控法来进行监控.基于这些腐蚀监控技术,建...     

不锈钢在大型尿素装置中的应用和发展

本文阐述了大型尿素装置的腐蚀与选材，介绍了不锈钢在大型尿素装置中的应用和发展，讨论、分析了国产不锈钢在这一领域面临的挑战、竞争和机遇。     

腐蚀控制手册在常减压装置停工检修中的应用

常减压装置是原油加工的第一道工序,由于原油中含有腐蚀性介质复杂,因此常减压装置整体腐蚀风险较高,安全隐患较大。某石化企业基于腐蚀控制手册的指导内容,对该企业的常减压装置中进行了腐蚀检查。腐蚀控制手册系统的描述了装置的工艺流程、选材情况、腐蚀机理、腐蚀回路分析及防控策略,对停工检修期间所发现的易腐蚀部位进行了预测并提出了建议。     

装置材料腐蚀寿命预测研究进展

本文探讨了装置材料腐蚀寿命预测的基本理论与方法，分析了装置材料腐蚀寿命预测的发展状况，阐述了利用计算机数据库和专家系统技术解决装置材料腐蚀寿命预测的问题的可行性和优越性。     

防腐蚀橡胶衬里在磷酸装置中的应用

在磷酸生产工程设备中所用的衬里材料几乎是橡胶衬里，只在个别部分另加衬砖。所用橡胶衬里必须承受设备里的多种负荷。如果仅选用某一种橡胶衬里，很难在所有的部位都达到理想的防腐蚀效果。作者胡为刚先生通过对磷酸生产工艺的分析，综合考虑生产装置各部位化学介质的腐蚀性．介质温度．压力及磨损状况，硫化的可能性等因素，选择最为合适的防腐蚀橡胶衬里。介绍KCH公司的橡胶衬里在磷酸行业的应用，并通过具体实例，介绍磷酸装置防腐蚀材料的选择。     

WS-1缓蚀剂在石油化工精制装置中的应用

分析了加氢精制装置分馏塔顶的腐蚀现象及腐蚀原因,采用了加注武汉国漆厂生产的WS-1缓蚀剂的防腐蚀措施,使设备腐蚀得到有效控制。     

不锈钢在稀硫酸介质中的腐蚀磨损行为

测定了300系不锈钢在稀硫酸介质中磨损率、摩擦系数及钝化膜破坏后的修复时间,还观察了磨痕形貌。实验表明高合金化的不锈钢磨蚀失重大于一般的304不锈钢。本文结果预示着发展耐磨蚀合金的道路不同于耐蚀合金。     

JYH系列缓蚀剂在石化蒸馏装置的应用

辽阳石化公司炼油厂蒸馏装置加工含硫量高的俄罗斯原油后,设备腐蚀严重.本文介绍了该公司所采用的注缓蚀剂和中和剂的防腐措施,及使用后的防腐效果.     

甲醇回收装置材料的腐蚀试验与选材依据

研究了不同材料在甲醇回收系统高温高浓氯化物介质中的耐腐蚀行为,通过大量的腐蚀试验和社会调查,选用了相应的耐腐蚀材料。     

超音速喷涂45CT涂层在KCl+K2SO4+Na2SO4熔融盐中的热腐蚀行为

目的研究超音速喷涂45CT涂层抗KCl+K_2SO_4+Na_2SO_4熔融盐腐蚀性能,了解45CT涂层在熔融盐中的防护及失效机制。方法将试样置于KCl+K_2SO_4+Na_2SO_4混合熔盐中,获得样品在熔盐中不同温度下的腐蚀动力学规律。采用XRD、SEM、EDS对高温腐蚀产物成分、结构、形貌进行分析。结果 45CT涂层在熔融盐中的主要腐蚀产物为Cr_2O_3、NaCrO_2。在600℃和650℃下,涂层能较好地保护基体,涂层上腐蚀产物层较薄;而在700℃下,涂层退化严重,涂层内有大量金属硫化物,基体中的Fe向涂层扩散。结论在高温条件下,涂层易发生硫化,导致涂层与氧化膜的弱结合。随着测试温度升高,涂层在KCl+K_2SO_4+Na_2SO_4熔融盐中的热腐蚀越严重,涂层失效加快。     

Effects of SO2 and SO3 on the Na2SO4 induced corrosion of nickel

The effects of SO₂ and SO₃ in the environment on the hot corrosion behavior of Ni in the temperature range 750–950°C has been studied. Below the melting point of Na₂SO₄ (884°C), rapid corrosion takes place by formation of a Na₂SO₄-NiSO₄ melt, which can penetrate the porous oxide scale and give rise to sulfide information by coming in contact with the metal. The distribution of the sulfides depends on the SO₂ level in the ambient gas. Continued corrosion occurs by a sulfidation-oxidation mechanism. At temperatures above the melting point of Na₂SO₄, accelerated degradation occurs via dissolution of the surface scale, followed by reprecipitation of the oxide in a nonprotective form.Deceased     

The effect of K2SO4 additive in Na2SO4 deposits on low temperature hot corrosion of iron-aluminum alloys

To understand the effect of K₂SO₄ additive in an Na₂SO₄ deposit on low temperature hot corrosion, the corrosion behavior of Fe-Al alloys induced by Na₂SO₄+K₂SO₄ was compared to that by Na₂SO₄ alone, and sulfation of Fe₂O₃ in the presence of either Na₂SO₄ or Na₂SO₄+K₂SO₄ was studied. It was found that K₂SO₄ additive promoted the low temperature hot corrosion, but did not change the corrosion-mechanism. Experimental results refuted the prior suggestions that the accelerated hot corrosion resulted either from the formation of K₃Fe(SO₄)₃ or from the stimulation of sulfation of Fe₃O₃. The earlier formation of the eutectic melt caused the accelerated hot corrosion, or in other words, the K₂SO₄ additive shortened the induction stage of hot corrosion.     

Initial atmospheric corrosion of zinc in presence of Na_2SO_4 and (NH_4)_2SO_4

1 Introduction In view of the widespread use of zinc, as metallic sheet or zinc coatings, it was desirable to study its corrosion behaviour in the wide variety of atmospheres. The atmospheric corrosion of zinc has been studied in field exposures as well …     

Cu-14Al-X合金在5.0%H2SO4溶液中的腐蚀行为

通过静态浸泡腐蚀实验、电化学实验、X射线衍射分析、扫描电镜、电子探针、光电子能谱等方法研究高铝青铜合金Cu-14Al-X在5.0%H2SO4溶液中的耐蚀性能及腐蚀行为。结果表明：在H2SO4溶液中,Cu-14Al-X合金有良好的耐蚀性能,合金中的（α＋γ2）共析体与β′相、α相和κ相相比,具有优先腐蚀倾向,合金主要发生脱铝腐蚀。腐蚀钝化膜的形成及热处理后合金各相成分趋于一致,均使合金耐腐蚀性能得到改善。     

304不锈钢在NaCl-(NH4)2SO4-NH4Cl溶液中的腐蚀行为

用电化学极化曲线和交流阻抗方法，研究了对304不锈钢（304SS）在3％NaCl和NaCl-（NH4）2SO4-NH4Cl混合溶液中的腐蚀行为．结果表明，在混合溶液中浸泡750h后，304SS仍然保持良好的钝化状态，其平均腐蚀电流密度为0．056mA／cm^2．根据交流阻抗研究结果，不锈钢在3％NaCl溶液中，主要表现出裸金属表面的点蚀和形成一定程度的钝化膜的特征，在2．0g／LNaCl、0．67g／L（NH4）2sSO4、2．3g／LNH4Cl混合溶液中，不锈钢表面形成稳定致密的钝化膜的典型特征．此钝化膜的电阻远小于腐蚀反应极化电阻．即使在形成良好的钝化膜的情况下，不锈钢所表现出的优良的抗腐蚀性能主要是由于金属表面活性点的钝化，而非钝化膜对离子导电或者对反应物／产物的扩散过程的阻隔作用．     

Acidic and basic fluxing of Ni-base superalloys in a 90Na2SO4-10K2SO4 melt at 1173 K

The influence of the electrode potential on the corrosion behavior of a series of Ni-base superalloys has been investigated in a (mole %) 90Na₂SO₄-10K₂SO₄ melt at 1173 K. Acidic fluxing occurs at positive potentials and basic fluxing at negative potentials. A protective scale is formed in an intermediate (neutral) potential range on high chromium-containing alloys such as IN-738LC, IN-939, IN-597, and IN-657. The breakthrough potentials for acidic and basic fluxing depend on the composition of the alloy. Alloys with low chromium contents such as IN-100 and IN-713LC do not form stable protective scales at any potential. Numerous sulfide phases have been identified in the scale and subscale, depending on potential, severity of attack, and material composition. NaCrS₂ only forms under basic fluxing conditions. Its presence can therefore be considered as an indication that basic fluxing conditions have existed.     

马来酸酐等离子体改性聚丙烯薄膜表面的硫酸腐蚀行为

以马来酸酐的等离子体聚合方法对聚丙烯薄膜表面进行了亲水改性,用FT-IR、接触角等分析手段研究了等离子体处理功率对改性薄膜表面的化学结构和亲水性能的影响以及薄膜表面的马来酸酐等离子体聚合物在高温强酸环境中的腐蚀行为.结果表明,马来酸酐等离子体聚合物可水解为聚马来酸结构,改性薄膜表面接触角达到43°～50°,接触角随处理功率的提高呈上升趋势.50W的马来酸酐聚合物的耐110℃、40%硫酸腐蚀性优于30W的马来酸酐聚合物;在高温硫酸介质的腐蚀环境下,马来酸酐的等离子体聚合物可通过磺化反应而引入亲水的磺酸基团,腐蚀后改性薄膜的表面接触角进一步降低至30°以下,获得了更佳的表面亲水性.     

Modulated Phases in the Ba2SiO4-Ca2SiO4 System of A2BX4, K2SO4-related Structures

Abstract

The A₂BX₄ family of K₂SO₄-related structures have long been of interest to crystal chemists, largely due to the numerous different polymorphs and complicated sequences of phase transitions they sometimes exhibit as a function of temperature. For most such A₂BX₄ compounds, there are essentially only two distinct structure types or parent structures — a high-temperature, ?hexagonal‘ form isomorphous to α-K₂SO₄ and a lower-temperature, orthorhombic form isomorphous to β-K₂SO₄. In addition to these two prototype structures, however, there often exist weakly distorted, or modulated, variants. In the case of the Ba_2-xCa_xSiO₄ system, five such modulated variants have been found via an electron diffraction study and characterized. The characteristic satellite extinction conditions associated with the weak satellite reflections have been used to determine displacement eigenvectors and atomic displacement patterns associated with each of the observed modulation wave-vectors. The widespread occurrence of modulated phases within the A₂BX₄ family of K₂SO₄-related structures suggests an almost chronic instability to displacive modulation.