烧结钕铁硼永磁材料腐蚀机理与表面防护技术

介绍了烧结NdFeB永磁材料在几种典型环境中的腐蚀机理,阐述了目前采用的NdFeB表面防护技术及研究进展情况,以及作者研究开发的烧结NdFeB永磁材料的表面防护涂层技术.     

镀硬铬时钢铁工件的局部腐蚀与防护

从活塞环基体的耐蚀性和微观电池腐蚀、宏观电池腐蚀、电偶腐蚀、氢去极化等方面探讨钢铁工件在镀铬过程中的腐蚀机理及腐蚀控制因素。并提出具体的防护方法。     

工业锅炉常见的腐蚀与防护

分析了工业锅炉常见的腐蚀及发生机理，并提出了相应的防护措施。     

镁合金汽车零件的腐蚀与防护

随着镁合金在汽车工业中应用的快速增长，镁合金的腐蚀防护变得非常重要，尤其是对外部零件。讨论了镁合金汽车零件的腐蚀问题以及防护方法，重点论述了汽车外部零件的腐蚀防护方法，并对镁合金电偶腐蚀及其防护进行了讨论。     

飞机结构的腐蚀与防护

飞机结构的腐蚀防护与控制技术是航空武器装备研究的重要领域,是发展航空武器装备必不可少的技术之一。飞机结构的腐蚀防护与控制贯穿于飞机方案论证、详细设计、生产制造和保障维护的全寿命周期,是一项重要且复杂的系统工程。因此,在飞机结构的设计阶段,就需结合飞机的服役环境,引入大量的防腐蚀设计,来综合提高飞机的抗腐蚀能力,从而保证在服役期间飞机平台的安全性和功能性。本文结合飞机结构常见腐蚀类型和腐蚀发生的原因,提出了飞机结构设计时的腐蚀防护与控制的方法。     

航空工业腐蚀与防护技术的发展

我所的金属腐蚀与防护研究室是我国航空系统腐蚀与防护研究中心。35年来,不仅在高温腐蚀与防护、表面处理、航空产品防锈封存等方面,同时也在应力腐蚀、大气腐蚀等方面开展了大量的试验研究工作,取得了不少研究成果。在飞机制造、新机研制、故障分析等方面发挥了一定的作用,为航空工业作出了应有的贡献。     

镁合金的腐蚀与防护研究进展

综述了镁合金的腐蚀现状包括腐蚀机理、腐蚀类型和负差数效应,总结了提高镁合金耐腐蚀性能的途径,并提出了进一步的研究与开发方向.     

热镀锌工业设备用钢铁材料耐锌液腐蚀的研究进展

在进行热镀锌工艺生产时,稳定辊、沉没辊、轴套等设备在连续运转过程中与锌液发生强烈腐蚀反应,明显降低设备使用的寿命,是热镀锌行业亟待解决的问题之一。针对热镀锌工业钢铁设备存在的腐蚀问题,从材料和机理角度综述了几类工业设备用钢铁材料的耐锌液研究进展,总结了研究中存在的不足,介绍了对锌液腐蚀产生重要影响的"Sandelin"效应,指出基于"Sandelin"效应研究耐锌液腐蚀性材料将成为今后重要的研究方向。     

影响钢铁大气腐蚀的因素

降雨可加速大气腐蚀速度亦有减缓作用,每种金属都有一个产生大气腐蚀的临界湿度。一般说来,相对湿度愈大,金属的腐蚀也愈大,湿度、空气中的尘粒、盐粒及SO_2是大气腐蚀的重要因素。     

环氧氯丙烷装置的腐蚀与防护

环氧氯丙烷是一种重要的有机化工原料和精细化工产品,用途十分广泛.其生产方法主要有丙烯高温氯化法和乙酸丙烯酯法两种.     

Effect of stress ratio on the cyclic tension corrosion fatigue life of notched steel BS970:976M33 in sea water with cathodic protection

Steel conforming to BS970:976M33 has been fatigue tested in notched form in air and in synthetic sea water, both freely corroding and cathodically protected at −1050 mV with respect to the saturated Ag/AgCl reference electrode. The cyclic and mean stresses were varied to study the effects of changes in the stress ratio, R(σ_min/σ_max), from 0.05 to 0.75, on the fatigue life response. Compared with the fatigue performance obtained in air at R=0.05 free corrosion lowered the fatigue strength at 10⁶ cycles to failure from 430 MPa to 135 MPa and cathodic protection changed it to 270 MPa. In each condition changes in R from 0.05 to 0.5 lowered the fatigue strength in the short life range by approximately 50% but had a much smaller effect, of approximately 10%, at a fatigue life of 10⁶ cycles.     

Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

Abstract

We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca₁₀(PO₄)₆(OH)₂. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.     

Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca₁₀(PO₄)₆(OH)₂. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.     

乙二醇在制冷系统中的腐蚀及防护研究

介绍乙二醇的物理化学性质,以及作为载冷剂在制冷系统中的应用情况,举例说明乙二醇溶液在制冷系统中的腐蚀现象,对其形成原因进行深入分析,提出添加缓蚀剂等防护措施。     

脉冲电流处理对X70管线钢腐蚀性能的影响

测量了X70管线钢在NS4溶液中的极化曲线,研究了高密度脉冲电流处理对其腐蚀性能的影响,结果表明,高密度脉冲电流处理导致X70管线钢的晶粒细化,使其内部活性区减少,提高了管线钢的耐局部腐蚀能力,X70管线钢的耐局部腐蚀能力随着脉冲电流密度的提高而增强,腐蚀产物的分布也更加均匀细密。     

Study on steel corrosion in different seabed sediments

A series of simulation experiments on carbon steel (A₃ steel) and low alloy steel (16 Mn steel) in marine atmosphere (MA), seawater (SW) and seabed sediment (SBS) including rough sea sand, fine sea sand and seabed mud were carried out indoors for a year or so by means of individually hanging plates (IHP) and electrically connected hanging plates (ECHP). The corrosion of steels in SBS was mainly due to the macrogalvanic cell effect. The steel plates at the bottom of SBS, as the anode of a macrogalvanic cell, showed the heaviest corrosion with a corrosion rate of up to 0·12 mm/a, approximately equal to that of steel plates in marine atmosphere. The test results showed that the corrosion rates of A₃ and 16 Mn steel in marine environment were in the order: MA>SW>SBS by the IHP method; and MA>SBS>SW by the ECHP method. The corrosion rates of steels in the water/sediment interface were directly proportional to the grain size of the SBS by the ECHP method, but those of steels in the water/sediment interface did not vary with the grain size of SBS by the IHP method. The corrosion rate of low-alloy steel was a little higher than that of carbon steel. The results of this study have important applications for design of offshore steel structures such as oil platform, pier, and port.     

聚苯胺防腐蚀电化学方法研究

本文综述了国内外在聚苯胺 (PANI)防腐研究中一些常用和新颖的电化学方法 ,指出其测试原理、过程和结果 ,表明PANI有良好的防腐效果。     

High temperature corrosion performance of Q235 steel in sulfur-bearing solution

The high temperature corrosion performance of Q235 steel in sulfur-bearing solutions as a function of temperature, test time, and sulfur content was investigated by weight loss measurements in this study. The results indicate that the corrosion behavior of Q235 steel in sulfur-bearing solution is directly related to the experimental temperature, immersion time and sulfur content. Higher temperature leads to a higher corrosion rate of the steel. The corrosion rate increases during the initial test time and then decreases with increasing the test time. As the sulfur content increases in the solution, the corrosion rate increases, and further increasing the sulfur content leads to a decreased corrosion rate.     

Effect of environment on corrosion characteristics of newly developed DMR-1700 structural steel

Abstract

The corrosion resistance of any metallic material depends on the environment to which it is exposed. DMR-1700 steel is a material for structural applications that has been recently developed at Defence Metallurgical Research Laboratory by changing the chemistry of alloying elements. Therefore, a detailed understanding of its corrosion characteristics under different environmental conditions is essential. In the present paper, we report the results of a systematic corrosion study that was carried out on the new steel to determine the effect of the environment on the protective nature of the oxide scale that forms on its surface under different environmental conditions. Furthermore, the oxide scale as well as the resistance to pitting and crevice corrosion were studied in various environments. The surface morphologies of the corroded steels were observed under a scanning electron microscope (SEM) to determine the nature of the corrosion. On the basis of studies by different techniques, DMR-1700 steel is recommended for the manufacture of components used in various systems in conjunction with the application of an appropriate protective coating to improve its resistivity to corrosion.     

杂散电流腐蚀及其对牺牲阳极阴极保护的影响

杂散电流的存在，加速了地下结构件的腐蚀，并对阴极保护系统造成不利的影响。在地下结构密集区更是如此。本文就杂散电流腐蚀、杂散电流对阴极保护系统的影响以及防止方法作了论述。