钢结构电弧喷涂锌铝复合涂层长效防腐工艺

针对钢结构的常用防腐方法，通过工程实例，介绍电弧喷涂锌铝复合涂层防腐的新工艺．该工艺对钢结构长效防腐在提高效率、增加防腐性能方面具有一定的参考价值。     

钢结构电弧喷涂锌铝复合涂层长效防腐工艺

针对钢结构的常用防腐方法,通过工程实例,介绍电弧喷涂锌铝复合涂层防腐的新工艺.该工艺对钢结构长效防腐在提高效率、增加防腐性能方面具有一定的参考价值.     

除氧器水箱的防腐处理

介绍高频脉冲超音速电弧喷涂技术在江西某电厂#300MW机组除氧器水箱防腐方面的应用,详细介绍了该种工艺的原理、使用材料等。     

热喷涂技术在电站设备中的应用

分析了电站设备中的电站锅炉、风机、磨煤机等设备的损耗原因,介绍了使用热喷涂技术对设备进行防护的措施。可以使用电弧喷涂技术、等离子喷涂技术或火焰喷涂技术喷涂高温材料的方法防护并维修电站锅炉的锅炉四管,喷涂耐磨材料防护并维修风机和磨煤机等。     

领先世界的“金属防腐”攻关

工业发达国家每年腐蚀造成的经济损失约占国民生产总值的2-4%,我国每年因腐蚀造成的经济损失至少有二百亿元。对此,一种金属防腐题目--超音速电弧喷涂技术在世界各国材料保护专家相互竞争研究的情况下,由我国一举攻克。     

电弧喷涂工艺参数对4Cr13合金涂层结合强度的影响

以雾化空气压力、喷涂电压、喷涂电流和喷涂距离等4个电弧喷涂主要工艺参数为因素进行正交试验,每个因素设置3种水平。采用自主研发的新型4Cr13合金药芯丝材,通过高速电弧喷涂设备在Q235钢板上制备涂层,分别考察这些参数对涂层与基材结合强度的影响规律,从而获得基于结合强度的最优电弧喷涂工艺参数,为制备高综合性能的涂层打下良好基础。     

利用PLC解决电弧喷涂的推、拉式送丝机构的同步问题

在电弧喷涂中利用PLC实现推、拉式送丝机构以解决传统的推式送丝机构在比较长的送丝软管中送丝时容易发生堆丝和喷涂中出现电弧不连续或断弧的现象.     

表面工程技术在绿色再制造工程中的应用

阐述了绿色再制造工程产生的背景、涵义,以及绿色再制造工程的研究对象、研究体系及研究方法,介绍了表面工程技术中的电弧喷涂技术及电刷镀技术,指出了若干表面工程技术在绿色再制造工程实际应用中的重要作用.     

钢结构的防腐处理

近几年钢结构建筑的发展异常迅猛。钢结构的广泛应用也暴露出一系列的缺点,较为严重的是钢结构的腐蚀。对钢结构防腐处理进行了综述。     

钢结构腐蚀及长效防腐方法介绍

近年来我国钢结构建筑发展迅速,充分利用了钢结构的长处。但是,易腐蚀是钢结构的不足之处,影响了钢结构的耐久性应用。本文从腐蚀对钢结构的影响、自然环境下钢的腐蚀规律、钢结构常用防腐方法以及热浸镀锌特点及应用等方面对长效防腐体系进行了综合的阐述,为钢结构的长效防腐体系的选择提供了参考。     

Corrosion process detection of tinplate in deaerated functional beverage by EIS

The corrosion process of tinplate in deaerated functional beverage was investigated by using electrochemical impedance spectroscopy (EIS) combined with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The results reveal that the uncoated tinplate shows a poor corrosion resistance and the corrosion type is detinning. During the initial stage of immersion, EIS spectrum consisted of two capacitance arcs with obvious time-constant dispersion effect, which was attributed to the two-dimensional and three-dimensional inhomogeneous distribution of the electrode surface. With the increase of immersion time, the capacitance arc of high frequency shrunk and degenerated, due to the corrosion of tin coating. The pore resistance of tin coating and the charger transfer resistance of substrate, which are determined from the electrochemical equivalent circuit, can be used as the indicators of tinplate corrosion process. The decrease of the pore resistance of tin coating indicates that the corrosion degree of tin layer becomes more severe, whereas the decrease of the charger transfer resistance of substrate implies that the corrosion degree of steel substrate also becomes more severe as the immersion time prolongs.     

Surface treatment of 0Cr19Ni9 stainless steel SMAW joint by plasma melting

Micro-plasma arc surface melting of 0Cr19Ni9 shielded metal arc welding joint with a micro-plasma arc welder produced a thin surface melted layer with a refined microstructure. The surface treatment changed the anodic polarization behavior in 0.5 mol/L H2SO4 solution. The polarization tests showed that for the as-welded joint both the heat-affected zone and the weld metal decreased in resistance to corrosion compared with the as-Received parent material while for the micro-plasma arc surface melted joint the corrosion resistance increased significantly. This increase in corrosion resistance is attributed to the rapid solidification of the melted layer. Rapid solidification of the melted layer refines its microstructure, decreases its microsegregation, and inhibits the precipitation of chromium carbides at the grain boundaries.received parent material while for the micro-plasma arc surface melted joint the corrosion resistance increased significantly. This increase in corrosion resistance is attributed to the rapid solidification of the melted layer. Rapid solidification of the melted layer refines its microstructure, decreases its microsegregation, and inhibits the precipitation of chromium carbides at the grain boundaries.     

瑞安市部分混凝土结构腐蚀破坏状况调查与原因分析

对瑞安市教座典型的混凝土结构构筑物的腐蚀破坏状况进行了调查分析．结果表明,飞云江沿岸混凝土结构腐蚀比较严重,许多构筑物的混凝土保护层过薄,有的出现了内部钢筋锈蚀、混凝土顺筋开裂和剥落等现象．主要原因有结构设计不合理、施工质量差、化学侵蚀等．     

High-Temperature Corrosion of Protective Coatings for Boiler Tubes in Thermal Power Plants

High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy ( SEM ), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAl coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings. It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal.     

X65管线钢在琼海、江津、青岛地区的五年大气腐蚀规律

开展武钢生产的X65管线钢在琼海、江津、青岛5年大气暴露腐蚀试验,得到了X65管线钢在三地的大气腐蚀速率的数据,实验结果表明试验钢在琼海站耐蚀性最好,江津站次之,青岛站最差。分析环境因素得出影响材料耐腐蚀性能的关键因素是SO2沉积率、H2S含量和SO2-4含量。通过数据回归拟合,得出X65管线钢在三个实验站的腐蚀规律均符合公式D=A·tn。     

耐候钢焊接接头锈层稳定化大气曝晒加速试验

利用锈层稳定化处理的耐候钢焊接接头,进行了大气曝晒(喷淋)加速试验,结果证明:经表面复合处理剂处理后的Q450NQR1耐候钢,腐蚀率显著降低,不仅提高了耐蚀性,而且也提高了抗局部腐蚀能力。经表面复合处理剂处理的焊接接头与非焊接样的腐蚀试验结果没有差别,说明表面复合处理剂适用于焊接接头的锈层稳定化处理。     

含氮节镍型QN2109Mo奥氏体不锈钢组织和性能

选择含氮节镍型QN2109Mo奥氏体不锈钢作为研究对象,采用XRD、TEM、SEM、EDS、摩擦磨损试验机和电化学工作站等检测手段,研究QN2109Mo不锈钢的组织结构、摩擦磨损性能以及耐腐蚀性能,并与316L不锈钢进行对比。实验结果表明:N原子主要以间隙固溶形式存在于QN2109Mo不锈钢中,对QN2109Mo不锈钢组织起到了细化作用,提高了QN2109Mo 不锈钢的硬度。在干摩擦状态下,QN2109Mo不锈钢的耐磨损性能优于316L不锈钢,其磨损机理为氧化磨损和磨粒磨损共同作用。在w(NaCl)为3.5%的溶液中,QN2109Mo不锈钢表现出比316L不锈钢更低的自腐蚀电流密度和更高的点蚀电位,具有更优异的耐NaCl 溶液腐蚀性能。     

不同Co含量对超音速火焰喷涂WC-xCo-3Cr涂层组织和性能的影响

通过超音速火焰喷涂工艺在Cr12模具钢表面上喷涂制备了WC-x Co-3Cr(x=8,10,12,14)涂层,并采用金相显微镜、扫描电镜、显微硬度仪和摩擦磨损试验机表征分析涂层的微观结构、显微硬度、耐磨损性能和耐腐蚀性,考察了不同Co含量对涂层组织和性能的影响。结果表明,Cr12模具钢超音速火焰喷涂后表面的耐磨损性能比喷涂前的基体耐磨损性能有较大的提高;表面硬度在不同程度上都得到提高,界面结合良好,其中WC-10Co-3Cr涂层的组织致密性最好、显微硬度最高、耐磨损及耐腐蚀性能最好。     

钢筋混凝土桥梁在大气环境作用下的耐久性评估和剩余寿命预测

根据混凝土碳化及其引起的钢筋锈蚀的机理,建立了钢筋混凝土构件的劣化模型。利用Monte Carlo模拟方法分别研究了一般运营和密集运营两种荷载模型下钢筋混凝土桥梁的时变可靠性,讨论了保护层厚度、混凝土强度、钢筋锈蚀损失率对混凝土耐久性的影响。研究表明：在服役过程中,由于大气环境的作用,混凝土碳化、钢筋锈蚀、桥梁结构可靠指标不断降低,混凝土的耐久性能不断下降;混凝土保护层厚度和混凝土抗压强度对可靠度指标的影响明显,而钢筋腐蚀率的影响不是很明显。     

Corrosion of carbon steel, zinc and copper by air pollution in Chongqing

This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H , were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose- response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.