铁锈渣对氧气生产的危害

介绍铁锈、铁锈渣对氧气生产的危害 ,分析一起因铁锈、铁锈渣引起的氧压机着火而殃及氧气囊燃烧的事故 ,针对分析的原因提出预防措施。     

Taxonomy for protective ability of rust layer using its composition formed on weathering steel bridge

For a quantitative evaluation of the protectiveness of a rust layer formed on a weathering steel bridge, the relationship between the corrosion rate of the bridge and the composition of the rust layers formed on the girders was first investigated. These corrosion rates were clearly classified by the protective ability index (PAI) of α/γ^∗ and (β + s)/γ^∗, where α, γ^∗, β and s are the mass ratio of crystalline α-FeOOH, the total of γ-FeOOH, β-FeOOH and the spinel-type iron oxide (mainly Fe₃O₄), β-FeOOH and spinel-type iron oxide, analyzed by XRD, respectively. The inequality of the former index α/γ^∗ > 1 expressed the protectiveness criterion of the rust layer, while that of the latter index, (β + s)/γ^∗< 0.5 or > 0.5, classified the corrosion rate of the non-protective rust layer. The PAI is useful for a quantitative evaluation of the protectiveness of a rust layer formed on a weathering steel bridge and is an important item for the corrosion assessment of the bridge.     

The effects of water pollution on the immersion corrosion of mild and low alloy steels

The short-term immersion corrosion of mild and low alloy steels in seawaters is known to be proportional to the concentration of dissolved oxygen (DO) in the bulk water. Longer-term corrosion is a function of the activity of sulphate-reducing bacteria and is influenced by the concentration of nutrients in the bulk water. These influences are examined in more detail for the corrosion of steels in the brackish waters of the River Thames and for several immersion corrosion sites on the Eastern Australian seaboard and in the North Sea. The published data sources were supplemented with plausible assumptions about environmental conditions. New interpretations of the data are provided based on the previously published model for immersion corrosion. For waters with negligible salinity and sulphate levels early corrosion loss was shown to depend on the dissolved oxygen content of the waters, and later corrosion loss was a direct function of nitrogenous nutrient (pollution) levels. This also applies to longer-term corrosion.     

Indoor atmospheric corrosion in Cuba. A report about indoor localized corrosion

Indoor weight loss of steel, chloride, sulphur compounds and dust deposition rate were determined in six storehouses having different characteristics. Relative humidity and temperature were determined in three storehouses. A model for indoor corrosion of steel depending on time of exposure and deposition of dust, sulphur compounds and chlorides is proposed. Dust deposition plays an important role indoors. The position of the sample has also a significant influence on corrosion. Indoor corrosion aggressivity in Cuban storehouses ranges in classification IC3 and IC4 according to the new ISO proposal of indoor aggressivity.A report about the presence of localized corrosion indoors (filiform like) using a special designed sample is made.     

玻璃钢筋混凝土的有限元计算与试验

钢筋混凝土广泛应用于土木工程领域，但其结构耐久性因钢筋本身的锈蚀成为现今急待解决的问题。人们一直在寻找对钢筋混凝土进行改良的途径，用玻璃钢筋代替普通钢筋是解决这一问题的一个有效的方法，为此进行了试验和ANSYS有限元分析，结果证明此法具有可行性。     

In situ observation of initial rust formation process on carbon steel under Na2SO4 and NaCl solution films with wet/dry cycles using synchrotron radiation X-rays

Atmospheric corrosion of steel proceeds under thin electrolyte film formed by rain and dew condensation followed by wet and dry cycles. It is said that rust layer formed on steel as a result of atmospheric corrosion strongly affects the corrosion behavior of steel. The effect of environmental corrosiveness on the formation process and structure of the rust layer is, however, not clear to date. In this study, in situ observation of the rusting process of a carbon steel covered with a thin film of Na₂SO₄ or NaCl solution was performed under a wet/dry repeating condition by X-ray diffraction spectroscopy with white X-rays obtained from synchrotron radiation. The present in situ experiments successfully detected initial process of the rust formation. In the early cycles, the rust constituents were not well crystallized yet, but the presence of Fe(OH)₂ and Fe(OH)₃ was confirmed. In the subsequent cycles, two different solutions resulted in difference in preferential phase of the rust constituents. α-FeOOH was preferentially formed in the case of the Na₂SO₄ solution film, whereas β-FeOOH appeared only under the NaCl solution film.     

细炻砖铜锈缺陷研究

细炻砖作为仿古砖的一个重要组成部分一直在家庭装修中被广泛应用。在细炻砖的生产过程中,铜锈在浅色版面中容易显露出来,占总缺陷的比例比较大,也降低了产品的品质。本文用XRF对原材料和坯体配方进行了定性分析,用SEM对铜锈进行了表面形貌分析,用EDS对铜锈进行了元素分析。结果表明,铜锈主要是原料中的有色金属杂质引起。通过加强浆料的过筛,降低浆料的细度可以有效减少铜锈的产生。     

大理石表面锈斑的事故树分析

大理石饰面材料在使用过程中,容易受到人为因素和环境的影响,致使大理石丧失了其保护建筑物墙体、美化建筑物等基本功能,也直接影响着大理石的使用寿命。在大理石材料产生的众多病症中,锈斑是最为常见的。通过安全系统工程的事故树分析方法,作者对引起大理石表面锈斑形成的各个因素进行系统分析,建立以大理石表面产生锈斑为顶上事件的事故树。通过对大理石表面产生锈斑事故树的分析,得到了事故树的最小割集、最小径集和结构重要度,为大理石饰面材料表面产生锈斑的预防提供了可信的参考依据,并给出了大理石锈斑的防治措施。     

Characterization of black rust staining of unpassivated 55% Al–Zn alloy coatings. Effect of temperature, pH and wet storage

Wet storage staining is a phenomenon that occurs on both zinc coated and 55% Al–Zn coated steel sheets during shipment or storage in damp conditions. Whereas zinc coated sheets form white corrosion products, 55% Al–Zn coated steel sheets form black corrosion products. The effect of temperature, pH and wet storage on the occurrence of black rust staining of unpassivated Aluzink samples has been investigated in the laboratory in terms of corrosion product formation and composition. A characterization of corrosion products formed has been performed mainly based on scanning electron microscopy with X-ray microanalyses (SEM/EDS) for morphological and quantitative analyses and X-ray diffraction techniques (XRD) for crystalline phase identification. Black rust formation is strongly related to alkaline pH regions and is enhanced by the temperature. All black panels show the presence of Bayerite (Al(OH)₃), mainly formed on the aluminum rich dendrite branches and a basic zinc aluminum carbonate (Zn₆Al₂(OH)₁₆CO₃·4H₂O) formed in the zinc rich interdendritic alloy regions in contact with air. Blackening of Aluzink surfaces is connected to differences in optical properties of embedded metallic zinc and/or aluminum particles of different shape and size in the corrosion layer.     

Enhancement the Adhesion between Epoxy Coating and Rusted Structural Steel by Tannic Acid Treatment

An eco-friendly rust converter treatment based on tannic acid was optimized by orthogonal experiment, and the adhesion of the epoxy top-coating system was evaluated. The results showed that the adhesion between the epoxy coating and the rusted steel after treatment was enhanced from 1.93 to 5.97 MPa. This adhesion improvement was attributed to the formation of the micro-cracked tannic conversion layer and the increase of the compactness of the rust layer. The failure analysis suggested that the remainder rust was still the key issue for the further adhesion improvement of the coating system.