共查询到17条相似文献,搜索用时 171 毫秒
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介绍了一种 201、304 不锈钢通用发黑工艺。研究了着色液各组分和挂具的材质对黑色膜性能的影响。着色的最佳配方与工艺为:CrO3165 g/L,H2SO4310 mL/L,H3PO460 mL/L,添加剂 A(铵盐)60 g/L,添加剂 B(过渡金属元素的硫酸盐)143 g/L,着色温度 91 95℃,着色时间 20 25 min,以 304 不锈钢丝作挂具。在最佳配方与工艺条件下,201、304 不锈钢黑板的膜层均匀、黑亮,耐蚀性能均优于对应的基体,耐磨擦性能优越。 相似文献
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以多巴胺修饰304不锈钢为基体,采用溶胶凝胶法和自组装成膜法制备了SiO2基、TiO2基和SiO2-TiO2混合基有机-无机杂化涂层。探讨了钛酸四丁酯、正硅酸乙酯和11-巯基十一烷酸(MUA)在不锈钢基体上的成膜性和成膜后的抗腐蚀性能。借助金相显微镜观察了不锈钢基体上的杂化膜的显微形貌,塔菲尔曲线和电化学阻抗谱对比分析了杂化膜的抗腐蚀性能。结果表明,MUA和TiO2、SiO2能复合成膜,膜的致密性好,具有可重复性,且引入TiO2和SiO2后,其抗腐蚀性能有较大幅度提高。 相似文献
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介绍了一种不锈钢黑色转化工艺。研究了温度和着色液主要组分对转化工艺的影响,并对黑色转化膜的成分、耐磨性、耐热性、耐蚀性等性能进行分析。得到不锈钢着黑色的最佳工艺条件为:铬酸酐175g/L,浓硫酸275mL/L,添加剂A225g/L,温度80°C。铬酸酐——浓硫酸复配组成影响转化膜的色泽和均匀性。随添加剂A含量的增加,转化膜颜色依次为灰、黑、蓝。不锈钢黑色转化膜的主要成分是Fe2O3和Cr2O3,膜厚为0.478μm,膜层黑度深,光亮度、耐热性和机械加工性能优异,耐腐蚀性和耐磨性均优于不锈钢基体。 相似文献
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为提高304不锈钢双极板的耐腐蚀性能,分别采用直流和脉冲电刷镀铅对其表面改性.采用电化学方法测定了改性前后304不锈钢在模拟PEMFC环境下的极化曲线,在扫描电镜(SEM)下观察了模拟腐蚀后的表面形貌,并用伏安法测量了改性前后304不锈钢的接触电阻.在模拟PEMFC环境中,改性后304不锈钢自腐蚀电流密度由10.83μA/cm^2下降至6.18μA/cm^2.经200 h模拟腐蚀后,304不锈钢表面发生点蚀,而改性不锈钢板表面完整,未观察到明显腐蚀.改性后的接触电阻也有所降低.结果表明,电沉积铅能有效提高304不锈钢在模拟PEMFC环境中的耐腐蚀性能,可望满足PEMFC环境下长期耐腐蚀的要求. 相似文献
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不锈钢电解着色工艺及电化学性能 总被引:4,自引:0,他引:4
对1Cr17铁素体不锈钢电解着黑色工艺和膜层的电化学性能进行探讨。本工艺具有发黑速度快,色泽均匀,较好的抗蚀性能。电解着色不锈钢表面形成铬的复合氧化膜,增强了钝性,使得自然电位和阳极极化电位正移,提高了膜层的电化学稳定性能。 相似文献
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使用硝酸和重铬酸钾的混合液对304不锈钢板进行了钝化处理。研究发现:不锈钢表面钝化过程伴随着钝化膜的生成和溶解。与304不锈钢板相比,钝化膜中铬和氧的质量分数提高。钝化膜主要由金属氧化物和金属氢氧化物构成。经过钝化处理后,304不锈钢板的自腐蚀电位正移,自腐蚀电流密度降低,膜电阻升高,耐蚀性增强。 相似文献
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Mechanical and electrochemical behavior of nanocrystalline surface of 304 stainless steel 总被引:1,自引:0,他引:1
This paper reports our recent studies on nanocrystalline surface layer of 304 stainless steel (304SS) produced using a sandblasting and annealing process. The grain size of the sandblasted surface layer was less than 20 nm. Mechanical and electrochemical properties of the nanocrystalline surface and its passive film were investigated using nano/micro/-indentation, micro-scratch, scanning Kelvin probe (SKP), potentiodynamic scanning and electrochemical scratch techniques. It was demonstrated that the nanocrystalline surface was markedly superior to that of original 304SS with enhanced passive film. The polarization, electrochemical scratch and SKP measurements indicated that the nanocrystalline surface had higher resistance to corrosion, greater capability of repassivation and higher chemistry stability. All results demonstrated that the nanocrystallization surface did not only enhance the mechanical properties of the surface layer and its passive film, but also benefited the passivation capability of the steel with improved corrosion resistance. 相似文献
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By employing Mott-Schottky analysis in conjunction with the point defect model (PDM), we compared donor density and donor diffusion coefficients in the passive films formed on the surface of nanocrystallized bulk 304 stainless steel (NB304ss) and cast 304 stainless steel (304ss) in 0.05 mol/L H2SO4 + 0.25 mol/L Na2SO4 solution. The donor density at the metal/film interface of the NB304ss was lower than that at the metal film interface of the cast 304ss. Based on the Mott-Schottky analysis, an exponential relationship between donor density and formation potentials of the passive films on the NB304ss and the cast 304ss was built up. The results showed that the donor diffusion coefficients in the passive film formed on the surface of NB304ss was lower than that in the cast 304ss. The lower donor density and the lower diffusion coefficient restrained the electrochemical reaction in the passive film and improved the stability of the passive film. That is the reason why the passive film formed on the NB304ss was more protective. 相似文献
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M. DRogowska H. Ménard A. Lasia L. Brossard 《Journal of Applied Electrochemistry》1996,26(11):1169-1177
The effects of applied d.c. potential and polarization time on the passivation of stainless steel 304 (SS304) were investigated in deaerated 1 M NaHCo3 aqueous solutions at pH 8. Electrochemical impedance spectroscopy was used in conjunction with a rotating disc electrode. The data were analysed by considering an equivalent circuit. The changes in impedance parameters at applied d.c. potential signal changes in the properties of passive films on SS304 and allow to distinguish the parameters at low potential (–0.6 to 0.3 V vs SCE) from a different one at high potential (0.5 to 0.8 V vs SCE). The oxidation reactions were controlled by both charge transfer and mass transfer processes. Diffusional resistance was high for both passive films and was considered to represent the resistance to movement of ions or vacancies through the surface layer of oxide films. It is deduced that the passive film present in the low potential region is partially dissolved at 0.4 V vs SCE and that a new passive film is formed in the higher potential region. The equivalent circuit used to obtain the best fit and the fitting parameters was dependent on the electrode potential and the polarization time. The reproducibility of the impedance spectra at constant potentials demonstrate that the passive film formation is highly irreversible process. No traces of localized corrosion were detected but, for a high potential and long polarization time, the electrode surface coloration to a uniform gold colour confirms the film thickening. 相似文献