镀锌层高耐蚀彩钝工艺

采用正交实验确定了镀锌钝化最佳工艺配方为14g/LCrO3,5g/L辅助钝化剂MH,5g/L HNO3,7g/L ZnSO4,0.7g/L KMnO4.研究了各工艺参数对钝化膜的影响.该钝化液性能稳定,使用寿命长;膜层为彩虹色,耐蚀性好.醋酸铅（ρ=50g/L）点滴实验氰化镀锌钝化层出现黑点的时间为98 s;NaCl（w=3%）溶液中浸泡,出现白锈时间为37 h;中性盐雾实验出现白锈时间在140 h以上。     

镀锌层军绿色无铬钝化剂的研究

开发了一种无铬军绿色钝化剂,通过单因素试验和正交试验研究了钝化剂的组成(包括硝酸镍、钼酸钠、丙二酸、亚硫酸钠和柠檬酸钠的用量)对钝化膜外观与腐蚀电流的影响,获得了较优的钝化剂配方为:硝酸镍15 g/L,钼酸钠20 g/L,丙二酸12 g/L,亚硫酸钠10 g/L,柠檬酸钠14 g/L。Q235钢碱性锌酸盐镀锌试样在p H为2.0~2.5、温度25~30°C的此钝化剂中钝化20~25 s,得到的钝化膜平整致密,呈军绿色,该钝化膜在(50±5)g/L的Na Cl溶液中浸泡,出现白锈和红锈的时间为16 h和72 h,具有较好的耐蚀性。     

镀锌层高耐蚀性三价铬彩色钝化工艺研究

采用正交试验法对镀锌层三价铬彩色钝化液组分进行了优化,研究了工艺参数对钝化膜外观和耐蚀性的影响。所得的最佳工艺条件为:20g/L氯化铬,7g/L硝酸钠,3g/L硫酸镍,8g/L醋酸,6g/L铵盐配位剂,温度25～35°C,pH2.5～3.0,时间50～60s。该工艺能获得外观艳丽、光亮、颜色均匀、附着力良好的膜层,其中性盐雾试验出白锈时间大于144h。     

镀锌层无铬彩色钝化剂的研究

通过单因素试验和正交试验研究了一种无铬彩色钝化剂中不同组分(包括硫酸亚铈、柠檬酸钠和硝酸钴)用量对钝化膜外观与耐蚀性的影响,得到较优的钝化剂配方为:硫酸亚铈50 g/L,柠檬酸钠15 g/L,硝酸钴20 g/L。采用最优配方在pH 1.5和温度20~30℃的条件下对镀锌层处理15 s,所得钝化膜平整、均匀,呈光亮的彩虹色。该钝化膜可通过24 h的中性盐雾腐蚀试验。     

新型氯化钾镀锌三价铬钝化剂和膜层耐蚀性

通过测定Tafel极化曲线、交流阻抗谱和进行盐雾试验,研究了新型三价铬彩色钝化剂SF-571和蓝白钝化剂SF-572对镀锌层耐蚀性能的影响,并与进口钝化剂进行对比。氯化钾镀锌工艺为:KCl200g/L,ZnCl250g/L,H3BO335g/L,柔软剂30mL/L,光亮剂1.5mL/L,25°C,25min,电流密度2A/dm2。电化学分析表明,所有镀锌层钝化膜在1%NaCl溶液中均存在钝化现象,采用自制钝化剂SF-571和SF-572所得膜层的耐腐蚀性能达到或优于用进口钝化剂所得膜层。对比膜层的表面形貌可知,自制钝化剂钝化所得膜层表面更平整、致密。     

镀锌铝镁钢板环保钝化剂涂层防护机理

低铝 [w（Al）=1%~3%]镀锌铝镁钢板具有良好的成形性,逐渐成为钢铁企业研究重点。针对热浸镀锌铝镁钢板的环保钝化问题,本研究利用原子力显微镜观察了不同有机无机复合无铬钝化剂在热浸镀锌铝镁钢板表面形成的钝化膜微观形貌,利用盐雾腐蚀实验检测钝化膜耐腐蚀性能,利用红外光谱 ATR法分析钝化膜的组成,利用拉曼光谱分析钝化膜烘干固化过程中化学键变化进程。结果表明：当有机无机复合钝化剂以硅烷为基础组分,添加钛盐、钒酸盐较添加锆盐和磷酸盐能生成更小、更完整的结晶颗粒,使得钝化膜具有更好的防锈性,同时有机组分聚氨酯较聚丙烯酸酯的钝化效果更好。     

锈蚀输电线路铁塔的漆前处理

研究了一种用于锈蚀镀锌钢板表面的磷化处理剂。通过正交实验和单因素实验获得了最佳配方:200 mL/L磷酸,60 mL乙醇,3.0 mL/L OP-10,1.0 g/L氧化锌,1.5 g/L螯合剂,2.5 g/L硝酸镍,2.5 g/L硝酸锰,1.0 g/L氯酸钠,2.0 g/L氟化钠。该磷化液能把锈层直接转化为保护膜,同时磷化锌层,所得的磷化膜耐硫酸铜点滴试验2~3 m in,NaC l浸泡试验超过15 h,附着力≤1。耐蚀性能实验48 h,漆膜无起泡、脱落和锈蚀现象。膜重:锈蚀板14~24 g/m2,热镀锌板5~8 g/m2。室内挂片试验6个月无返锈。该磷化液适用于锈蚀钢材、泛锈蚀镀锌钢材和完好锌层钢材。     

镀锌低铬钝化故障处理

0前言 镀锌低铬钝化从上世纪70年代中期起,由180g/L、40 g/L高铬二次钝化基础上降到2～5 g/L低铬钝化新工艺,并且钝化膜的耐蚀性基本上可达到高铬钝化的耐蚀性,初步解决了环境污染问题.本文将低铬彩钝化和白钝化常见的膜层缺陷、产生原因及处理方法,汇总如下.     

稀土钕对镀锌层三价铬蓝白钝化膜耐蚀性的影响

在三价铬钝化液中添加稀土钕,以提高三价铬蓝白钝化膜的耐蚀性。研究了钝化温度、pH、时间以及钝化液中稀土钕含量对钝化膜耐蚀性的影响,得到镀锌层三价铬蓝白钝化的最优工艺条件为:Cr2(SO4)3 18.9 g/L,Nd(NO3)3·6H2O 4 g/L,NaNO32.2 g/L,C6H8O7·H2O 0.7 g/L,CoSO4·7H2O 7 g/L,NaH2PO2·H2O3.4 g/L,NH4HF2 0.2 g/L,温度30°C,pH 1.9,时间30 s。钝化液中添加稀土钕可有效提高钝化膜的耐蚀性。在最佳工艺条件下,钝化膜在3.5%NaCl溶液中的腐蚀电位、腐蚀电流密度和交流阻抗分别为-1.231 V、0.568μA/cm2和1 937?·cm2,中性盐雾试验出现白锈的时间为93 h。     

镀锌层三价铬蓝白钝化工艺的研究

三价铬蓝白钝化对环境污染小,但钝化液成分较复杂,钝化膜耐蚀性及外观不如六价铬钝化膜.为此,本文探讨了工艺参数对钝化层外观和耐蚀性的影响,并得到了组分简单的镀锌层三价铬蓝白钝化工艺.钝化膜耐蚀性能好,经84 h的中性盐雾试验不产生白锈.     

Voltage decay at passivated zinc anodes

A study has been made of the passivating process at a zinc electrode in KOH solutions. Zinc electrodes were passivated at a constant overpotential and the current response during passivation was measured. The potential response after the passivating potential was removed was also measured.The current during passivation soon reached a semi-steady-state value which increased with increasing overpotential but varied only slightly with changing KOH concentrations.When electrodes were passivated at overpotentials >325 mV, the open circuit voltage decay showed an arrest, the duration of which decreased with increasing KOH concentration. This duration increased when ZnO was dissolved in the electrolyte, when the temperature was decreased, and when the passivating overpotential was increased.The results are interpreted by assuming that passivation is due to the formation of a film, possibly Zn(OH)₂, which can dissolve in the electrolyte. The potential of the electrode is a mixed potential.     

镀锌层高耐蚀性三价铬钝化工艺研究

通过添加适当的氧化剂和螯合剂,对镀锌层三价铬钝化溶液进行改性,控制溶液的pH,钝化温度和时间,利用对比试验对镀锌层钝化工艺进行研究,通过50g/L的NaCl溶液浸泡试验,探讨三价铬钝化工艺参数对钝化膜耐腐蚀性的影响,通过观察腐蚀面积对钝化膜层的耐腐蚀性能进行初步分析.结果表明:采用改性后三价铬钝化液进行钝化,镀锌层的耐...     

不同镀锌工艺三价铬钝化耐腐蚀性研究

采用中性盐雾试验和电化学阻抗谱,研究了酸性氯化钾镀锌、碱性无氰镀锌和碱性氰化物镀锌3种工艺所得镀锌层经三价铬彩色钝化后钝化膜的耐蚀性.结果表明:钝化后,酸性氯化钾镀锌层的耐蚀性最好,碱性无氰镀锌层次之,碱性氰化物镀锌层最差.在质量分数为1%的氯化钠溶液中,镀锌层钝化膜电阻的大小顺序为:酸性氯化钾镀锌>碱性无氰镀锌>碱性氰化物镀锌.酸性氯化钾镀锌钝化膜的耐蚀性较好可以与所得镀层中有机杂质夹杂较少有关.     

Activation of passivated titanium anodes from the electrolysis of MnO2

Titanium anodes with and without a MnO₂ precoat were passivated during deposition of electrolytic manganese dioxide and subsequently activated by cathodic reduction. The time dependance of the titanium voltage during passivation and during cathodic reduction was determined by the initial state of the surface. Nonactivated titanium passivated considerably faster than activated titanium with the same thickness of precoat. The application of cathodic currents to passivated anodes caused detachment of the precoat and reduction of the passivating film underneath the precoat. Reduction of the passivating film grown on precoated titanium seems to occur at a much smaller rate than reduction of the film grown on unprecoated titanium.     

Surface passivation and shape selectivity in hydrocracking over ZSM-5

The shape selectivity of ZSM-5 has been enhanced by passivating its external surface area by silation. This passivated zeolite is found to be superior for the selective removal of waxy material from a lubricating oil fraction by hydrocracking.     

Potential and current distributions along resistive electrodes

A simple theory of current and potential distributions along resistive electrodes is re-examined and generalized for non-linearized Tafel behavior. A model of a passivating electrode is discussed and the generalized theory extended to derive expressions for the current and potential profiles along a partially passivated electrode. The relevant expressions permit a predictive analysis of the feasibility of using the electrochemical passivation method for etch-stop control in fabrication of thin, single crystal silicon structures produced by anisotropic deep etching.     

镀锌层单宁酸钝化膜的耐蚀性

为提高镀锌层的耐蚀性,以氟钛酸钾、双氧水、硝酸为辅助成分,制备了单宁酸钝化液,并对低碳钢上的碱性镀锌层进行了钝化处理.通过质量分数为5%的NaCl溶液浸泡试验,确定了最佳钝化液组成和钝化工艺条件为:单宁酸40 g/L,HNO3 5 mL/L,氟钛酸钾10g/L,H2O2 60 mL/L,温度25℃,时间20～30 s....     

铝上浸锌层的无氰预镀铜工艺研究

研究了一种铜包铝线浸锌后的无氰预镀铜工艺。最佳镀液配方为:20~25g/L焦磷酸铜,320~350g/L焦磷酸钾,40~45g/L辅助配位剂A(氨羧化合物),15~20g/L辅助配位剂B(有机酸)。讨论了起始电流密度、温度、预镀时间及pH对镀层结合强度的影响,得出最佳工艺参数为:起始电流密度0.3~1.1A/dm2,温度25~40°C,预镀时间3min,pH8.0~8.8。     

改善焦炭热性能的探讨

取国内具有代表性的生产入炉煤,进行常规炼焦、捣固炼焦、配型煤炼焦、配黏结剂炼焦实验,并对常规焦炭进行钝化,以探讨改善焦炭热性能的可能性。结果表明,与常规焦炭相比,捣固炼焦、配型煤炼焦、配黏结剂炼焦反应后强度平均分别提高8.39%、8.20%、5.13%;采用质量分数1.0%的硼酸、硼砂、硼酸-硼砂-二氧化硅复合钝化剂处理焦炭,可使反应后强度分别提高6.59%、8.63%、6.10%。     

黄铜制品钝化处理新工艺

黄铜制品极易变色 ,须进行钝化处理。由于传统铬酸盐钝化工艺存在钝化膜色泽不均匀及红斑等缺陷 ,采用二步钝化工艺 ,消除了传统钝化工艺的缺点。进一步提高了钝化膜的抗变色性能。