Q235钢镀锌层对钢/铝合金搅拌摩擦点焊接头性能的影响

通过在Q235钢板上电镀不同厚度的锌层,研究镀锌层厚度对钢/铝合金异种金属搅拌摩擦点焊接头性能的影响。利用拉剪试验、光学显微镜、扫描电子显微镜等分析手段对钢/铝合金异种金属搅拌摩擦点焊接头性能进行了分析。结果表明,镀锌层厚度在8~12μm的Q235镀锌钢与6061铝合金形成的点焊接头拉剪力较高。     

热浸镀锌技术的研究进展

介绍了连续热浸镀锌和批量热浸镀锌工艺及其适用范围,论述了热浸镀锌层的组织和性能,分析了合金元素、钢基体化学成分、热浸镀温度和热浸镀时间等因素对热浸镀锌层组织和性能的影响,介绍了热浸镀锌技术的应用领域和研究现状,对该技术的研究方向进行了展望。     

预镀铜对机械镀锌层性能的影响

研究了预镀铜对机械镀锌层的结合性能和耐腐蚀性能的影响。结果表明，有无预镀铜层附着性能都能达到相关标准要求。预镀铜层的存在使机械镀锌层的抗冲击破坏能力增加，而耐腐蚀性能有所下降，     

镀锌层在NaCl溶液中的腐蚀行为研究

采用腐蚀电位分析和电化学阻抗技术研究了经钝化的镀锌钢在不同浓度的NaCl溶液中的腐蚀行为.结果表明,镀锌钝化层在NaCl溶液中的腐蚀分为三个阶段:钝化膜的溶解、镀锌层的阴极保护和钢基体的腐蚀.浸泡初期主要受Cl-浓度影响,且浓度越高腐蚀越严重;浸泡中期,随着Cl-浓度增加镀锌层耐腐蚀性能先减小后增大,在5%NaCl溶液中耐腐蚀性最差.     

输电塔杆用热浸镀锌钢在模拟酸雨大气环境中的腐蚀行为

通过循环盐雾腐蚀实验模拟镀锌钢在酸雨大气环境中的腐蚀过程。采用腐蚀质量损失测试、扫描电镜(SEM)、能谱仪(EDS)和电化学技术分别对腐蚀48,84,132,180和228 h的镀锌钢试样进行测试分析,得到腐蚀动力学规律、腐蚀产物成分、锈层截面形貌以及表面锈层的电化学特性。研究了锈层对镀锌钢在酸雨条件下大气腐蚀的影响。动力学分析表明,腐蚀过程中镀锌钢的表面形成了具有较好保护性的锈层;电化学测试结果表明,锈层的保护性呈现随腐蚀时间的延长先增强后减弱的变化过程。     

镀锌钢接地网及其钎接技术研究

介绍了接地材料的用材种类、连接方法、市场用量,分析了镀锌钢接地材料存在的价值和意义。阐述了镀锌钢接地材料钎接的可行性与技术经济性,并研制了用于镀锌钢接地材料连接用Cu-Zn基钎料。对该钎料钎焊接头进行了力学性能、物化性能测试,镀锌钢接头焊缝金属的电阻率为0.0702Ω.mm2/m,其第一锈点时间为30 h,接头的拉伸破断力值为38 kN。上述指标均优于镀锌钢电弧焊接头。此外,其过渡层均匀平顺,无明显缺陷组织,验证了Cu-Zn基钎料广泛应用于镀锌钢连接的可行性。     

扩散处理工艺对镀锌层组织和性能的影响

研究了扩散处理工艺对要进行热冲压成形的钢板含0.17%Al(质量分数)的镀锌层组织和性能的影响。结果表明,随着扩散处理温度的提高和保温时间的延长,镀锌层组织和性能发生了明显的变化,在520℃扩散处理20 s后镀锌层表面的ζ相消失。随着扩散处理温度的升高,镀锌层与钢基体界面处的Γ相增厚,在500~520℃时增厚尤为明显。当镀层由ζ相和疏松的δ相或者由疏松的δ相和Γ相构成时,镀层塑性较好。而致密的δ相会明显降低镀层的塑性。     

Q235钢在溶液中微弧镀锌的组织与性能变化

对Q235钢在溶液中的脉冲微弧镀锌进行了研究。在固定的工艺参数条件下,对Q235钢试样进行微弧镀锌处理。利用金相显微镜、粗糙度仪分析测定试样表面金相组织、镀锌层组织变化、镀锌层粗糙度变化,并用剥离法测试表面附着力,探讨溶液中微弧镀锌的机理。结果表明,在电压170 V、电流10 A、脉冲频率172 Hz时,对试样微弧镀锌30 s后,试样外观形貌和镀锌层与基体附着力最佳,表面粗糙度明显低于处理前,镀锌层分布较均匀。     

机械镀锌中超声功率对镀层耐腐蚀性能的影响

目的探究超声波功率对镀层耐腐蚀性的影响规律。方法将超声波功率分为50,70,90,110W 4个等级,利用湿法超声机械镀锌设备制备4种镀层。用多功能扫描电子显微镜观察镀锌层的微观表面形貌,并分析镀锌层厚度,测试镀锌层的耐腐蚀性能以及镀层与基体的附着强度。结果功率为50W时获得的镀层厚度最大,表面质量、耐腐蚀性能最差;功率为110W时获得镀层表面质量、耐腐蚀性能最好。结论随功率的增大,镀层表面质量明显提高,镀层耐腐蚀性有逐渐增加的趋势。     

镀锌钢板的锌层附着特性及成形性研究

文章针对4种不同种类的镀锌钢板开展了锌层附着特性和成形特性研究,深入分析了镀锌钢板的抗粉化和剥落性能以及锌层对钢板成形极限和极限拱顶高的影响。结果表明,对于镀层强度较高的热镀锌铁合金钢板,其抗粉化和剥落性能较差。且随着温度的升高,镀锌板的锌层脱落量增加。锌层对钢板成形极限的影响很小,但对极限拱顶高有一定影响。     

Development of new brightener for industrial zinc coating

An acidic sulphate bath solution has been developed by Hull Cell studies to electroplate industrial zinc coatings on mild steel. Histidine in combination with ninhydrin has been evaluated as a brighener for zinc. The brightness of the coating was enhanced in the presence of traces of additives: sodium taurocholate, polyvinyl alcohol, and ascorbic acid. Working conditions and plating bath composition were optimised to obtain a good quality zinc coating with current efficiency and throwing power of 100% and 35% respectively. The functional properties (adhesion, hardness, corrosion resistance and surface morphology) of the coating have been evaluated.     

Enhanced corrosion protection by powder coatings on hot rolled steel (HRS) for high-temperature applications

Hot rolled steel (HRS) has long been a major product to the motor industry for bodywork, as galvanised steel (zinc coatings), and it is widely used in building and as tinplate (including tin and chrome oxide coatings) for food, etc. can-making. Among more specialist uses its moderate production costs makes it suitable for the manufacturing process. In this study, newly developed corrosion protection enhanced silicone based powder coating was evaluated on hot rolled steel (HRS). The powder coating in this study was developed to withstand high temperatures up to 550°C without any degradation. In the study silicone resin was incorporated with fillers, corrosion inhibitors and fibres at various compositions to achieve maximum heat resistance and improved corrosion resistance. Protective behaviours of the differently formulated powder paints were investigated before and after heat exposure. The developed paint system was evaluated using various test methods such as heat resistance, salt spray, Electrochemical Impedance Spectroscopy (EIS), adhesion test and microstructure study using SEM. The evaluation of test results revealed that powder coating combining zinc dust particles and mineral fibres have better performance due to better corrosion and adhesion stability in the corrosive environment before and after heat exposure up to 550°C.     

输电铁塔防护用低表面处理涂料

针对锈蚀输电铁塔在防护过程中存在着除锈等级不高、涂层与基体表面附着力差的问题,开发了一种可用于锈蚀热镀锌钢表面的转化-稳定型低表面处理涂料,分析了各组分的作用,研究了磷酸锌、鳞片状锌粉、锈蚀转化剂用量及涂膜厚度对涂层性能的影响。对所制备的涂料进行实验室性能测试和户外应用试验,低表面处理涂料防腐蚀性能和施工性能均表现良好。     

湿热环境中碱性泥浆附着下镀锌钢板的腐蚀行为

通过在湿热环境中进行高温高湿条件下进行腐蚀实验,研究了在泥浆附着条件下汽车用热浸镀锌钢板的腐蚀行为,观察了腐蚀的发展过程,并利用SEM和XRD等手段对腐蚀产物进行了观察和分析.结果表明,镀锌板的泥浆腐蚀过程可分为形成白锈的镀锌层腐蚀以及形成红锈和黑锈的基体腐蚀2个阶段.基体腐蚀产物中γ-FeOOH含量较高,而且泥浆中Cl-的富集对腐蚀产物的保护性具有加速破坏作用.在较低温度时,腐蚀失重率逐渐降低;而在较高的温度下,腐蚀失重率则出现先降后增的转折点,主要原因是温度升高导致腐蚀界面反应加速.在腐蚀过程中,腐蚀电位会发生从低至高的跃迁,分别对应着镀锌层和钢基体的腐蚀过程.环境温度提高,将导致电位跃迁提前.     

Composite zinc-fly ash coating on mild steel

Zinc-fly ash composite coatings were deposited on mild steel substrates with the help of electrodeposition technique. Metallographic and chemical characterization of the produced composite coatings was performed with the aid of Scanning Electron Microscopy (SEM) and Electron Dispersive X-ray Analysis (EDX). The corrosion behaviour of the composite coated mild steel substrate was studied in a 0.3 M NaCl solution (pH = 5.5) by means of anodic polarization curves. The wear of the zinc-fly ash coating was also investigated by using a pin-on-disk apparatus. The composite coating exhibited increased wear resistance, compared to the pure zinc coating and the mild steel substrate. The adhesion strength between the zinc-fly ash coating and the mild steel substrate was examined with a scratch testing apparatus. The adhesion strength between zinc-fly ash composite coating and the mild steel substrate was found to be higher than that of the pure zinc coating to mild steel.     

Corrosion and corrosion test methods of zinc coated steel sheets on automobiles

The effect of zinc and zinc alloy coated steel sheets on perforation corrosion in actual automobiles and the relevant accelerated corrosion test methods were studied. The main factor affecting corrosion in the crevice of lapped panels was the coating weights of zinc and zinc alloys rather than the type of coating. Perforation corrosion process of galvanized steel in the crevice of lapped portion in automobiles was divided in four stages. Based on the analysis of corrosion in actual automobiles, a Perforation Corrosion Index, PCI for lapped steel panels was proposed. Assuming PCI for various accelerated corrosion test methods, the corrosion resistance of various types of coated steel sheets in actual environments was evaluated.     

Long-term factors influencing the adhesion of metallized zinc to concrete

Metallized zinc cathodic protection often is used to mitigate steel reinforcement corrosion in concrete. The zinc is flame or arc sprayed to the surface of the concrete structure to be protected. The metallized coating should be applied such that its adhesion to concrete is maximized. Factors believed to affect adhesion were investigated for pure zinc and a 85Zn-15Al alloy. On reinforced concrete samples polarized for more than 800 days at three different current densities, adhesion decreased. The reduction increased as a function of time and of the current density applied. When no current was applied, there was a small initial increase of adhesion with time. For the metallized samples that were freeze-thaw cycled, no loss of adhesion was found after 70 cycles.     

Über das korrosionsverhalten von stahlblechen,die mit verschiedenen Strahlmitteln entrostet und mit Zinkstaubanstrich versehen wurden

Corrosion behaviour of steel plate blasted with various media and coated with a zinc dust coating Steelplate which had been descaled by blasting with various blasting media was given a zinc dust coating and its corrosion behaviour was tested in salt spray and in the atmosphere. The surfaces blasted with sand, slag and corundum are superior in the salt spray test to those blasted with steel shot because the letter produces excessive roughness profiles. Under atmospheric conditions, however, corundum blasting appears to be superior. Brush application is better that spraying because the poor adhesion of spray coats facilitates underrusting.     

Study of role of phosphate coating properties on electrophoretic paint performance by EIS and simulated corrosion tests

The influence of phosphate bath chemistry on phosphate coating properties and, eventually, on corrosion resistance properties of electrophoretic (ED) painted steel samples was examined. Two types of zinc phosphate bath chemistry with different concentration of zinc and nickel ions, and different values of total acid, free acid, and accelerator content were studied. The phosphate bath with higher value of acid ratio (total acid/free acid), nickel ion concentration, and accelerator point produced the best phosphate coating on steel surface with globular microstructure, small crystal size, high P ratio, and uniform coverage. Phosphate coated and only alkali cleaned samples were cathodic ED painted. Their corrosion resistance properties were evaluated by salt spray test, cyclic corrosion test and electrochemical impedance spectroscopy. The relative increase in corrosion resistance of painted sample due to best phosphate coating was 1·4 to 1·8×. Paint adhesion of samples significantly deteriorated when painted without phosphate pretreatment.     

Ra 及 Rpc 对无铬耐指纹热镀锌板表面性能的影响

目的研究热镀锌板表面平均粗糙度Ra和峰值数Rpc对无铬耐指纹热镀锌板表面耐指纹性、耐腐蚀性和涂装性的影响。方法将Ra=0.6~1.1μm和Rpc=55~100的热镀锌板制成耐指纹板,采用X射线光电子能谱仪分析其组成,采用分光光度仪分析其耐指纹性,采用硫酸铜混合溶液滴定和盐雾试验方法检测其耐腐蚀性,采用涂漆和冲击实验检测其涂装性。结果耐指纹膜和锌层表面形成Si—O—Zn金属键,耐指纹膜除了物理结合,还通过化学键合的方式与锌层表面结合。在充分交联固化和化学键合的情况下,无铬耐指纹热镀锌板耐指纹性不受热镀锌板Ra和Rpc的影响;热镀锌板Ra值越低,耐腐蚀性越好;耐指纹膜单位质量为1.1 g/m2,Ra≤1.1μm时,耐指纹板72 h盐雾试验白锈面积不大于5%;热镀锌板Rpc值越高,无铬耐指纹热镀锌板涂装性越好,Rpc≥80时,耐指纹热镀锌板涂漆冲压后,漆膜完好。结论 Ra和Rpc对热镀锌板耐指纹性影响不大,对耐磨蚀性和涂装性影响显著。