非晶态Fe—W镀层铬酸盐钝化膜耐蚀机理探讨

Ｆｅ－Ｗ非晶镀层经铬酸盐钝化处理，可获得有装饰的含Ｃｒ钝化膜，经测定，孔蚀电位较钝化前正移１．６８Ｖ，明显改善了抗Ｃｌ＾－腐蚀的能力，ＡＥＳ与ＸＰＳ的分析结果表明，钝化膜由内外两层构成，外层为Ｆｅ（ＣｒＯ４）３．Ｃｒ２（ＣｒＯ４）３／Ｃｒ２（Ｃｒ２Ｏ７）３．Ｆｅ（ＯＨ）３／ＦｅＯＯＨ．ＷＯ３．ｎＨ２Ｏ等化合物，内层由Ｃｒ２Ｏ３，ＣｒＯ３，ＣｒＯＯＨ，ＦｅＯ，Ｆｅ２Ｏ３及ＷＯ３组成。钝化膜厚度约为６     

非晶态Fe－W镀层铬酸盐钝化膜耐蚀机理探讨

Ｆｅ－Ｗ非晶镀层经铬酸盐钝化处理，可获得具有装饰效果的含Ｃｒ钝化膜。经测定，孔蚀电位较钝化前正移１．６８Ｖ，明显改善了抗ＣＩ－腐蚀的能力。ＡＥＳ与ＸＰＳ的分析结果表明：钝化膜由内外两层构成，外层为Ｆｅ（ＣｒＯ４）３·Ｃｒ２（ＣｒＯ４）３／Ｃｒ２（Ｃｒ２Ｏ７）３·Ｆｅ（ＯＨ）３／ＦｅＯＯＨ·ＷＯ３·ｎＨ２Ｏ等化合物，内层由Ｃｒ２Ｏ３，ＣｒＯ３，ＣｒＯＯＨ，ＦｅＯ，Ｆｅ２Ｏ３及ＷＯ３组成。钝化膜厚度约为６０ｎｍ。该双层饨化膜有效地阻止了Ｃｌ－对基体金属的腐蚀。     

镀锌层表面有机复合铬酸盐防腐膜

研究了一种有机复合铬酸盐膜（ＫＤＰＣ）,其耐蚀性优于国产有机复合膜（ＢＧＵＦ）。这种新的复合膜是以电镀锌钢板为基板,由内外两层构成,内层为ＣｒＯ３Ｈ３ＰＯ４ＳｉＯ２系钝化膜,外层为含ＣｒⅣ,ＣｒⅢ和ＳｉＯ２的有机树脂涂膜。该复合膜不仅能有效地阻挡Ｈ２Ｏ,Ｏ２和Ｃｌ－对镀锌层的腐蚀,而且还能起到良好的缓冲作用     

几种Ni-Cr-Al墓低偏析高温合金的抗氧化性能研究

在１０００～１１００℃之间,对三种Ｃｒ、Ａｌ含量及微量元素Ｓ、Ｚｒ含量不同的Ｎｉ－Ｃｒ－Ａｌ基合金进行了恒温和循环氧化实验。结果表明,高Ｃｒ（１６Ｗｔ％）,低Ａｌ（３．５Ｗｔ％）、Ｓ（０．００５ｗｔ％）含量,且不含Ｚｒ的合金其氧化膜层主要由连续致密的Ｃｒ２Ｏ３外氧化层和树根状Ａｌ２Ｏ３内氧化层构成,氧化膜的粘附性较好。高Ａｌ（５ｗｔ％）,低Ｃｒ（９ｗｔ％）、Ｓ（０３００５ｗｔ％）含量,且不含Ｚｒ的合金其氧化膜主要由Ａｌ２Ｏ３,ＴｉＯ２,Ｃｒ２Ｏ３构成,氧化膜的粘附性较差,但在该合金中加入０．１Ｗｔ％Ｓ和０．１Ｗｔ％Ｚｒ,氧化膜的粘附性变好,而恒温氧化速率增加。文中对实验结果进行了综合分析。     

一种高速化学镀Ni-Cu-P合金工艺

开了一种高速化学镀Ｎｉ－Ｃｕ－Ｐ合金工艺,研究了镀液中ＣｕＳＯ１．５Ｈ２Ｏ浓度、ｐＨ值、温度对镀层成分、镀速的影响,并根据ＧＢ１０１２４－８８标准对镀层作了耐蚀性试验。结果表明,本工艺在各参数较大的变化范围内均可获得较高的镀速,最高镀速可达２８ｕｍ／ｈ,而且镀层具有较好的耐蚀性,该工艺条件下获得的镀层在５０％Ｈ２ＳＯ１（室温）和５０％ＮａＯＨ（９５Ｏ）中的耐蚀性远高于１Ｃｒ１８Ｎｉ９Ｔｉ、１Ｃｒ１８Ｎｉ１２Ｍｏ２Ｔｉ等不锈钢、碳钢以及Ｎｉ－Ｐ化学镀层。     

电镀锌钢板涂敷型低铬钝化研究

应用正交试验优选电镀钢板－ＣｒＯ３－Ｈ３ＰＯ４－ＳｉＯ２系钝化剂配方,研究钝化注ｐＨ值,钝化时间,干燥温度对钝化膜耐蚀性的影响,提出一种涂敷型低铬钝化新工艺。该工艺所得钝化膜稳定性好,其抗白锈能力是目前国产涂敷型铬酸盐处理镀锌钢板的３倍。文中还对ＣｒＯ３－Ｈ３ＰＯ４－ＳｉＯ２系钝化膜的形成机理和防护机制进行了初步探讨。     

几种Ni—Cr—Al基低偏析高温合金的抗氧性能研究

在１０００－１１００℃之间，对三种Ｃｒ，Ａｌ含量及微量元素，Ｓ，Ｚｒ含量不同的Ｎｉ－Ｃｒ－Ａｌ基合金进行了恒温和循环氧化实验。结果表明，高Ｃｒ，低Ａｌ，Ｓ含量，且不含Ｚｒ的合金其氧化膜层主要由连续致密的Ｃｒ２Ｏ３外氧化层和树根状Ａｌ２Ｏ３内氧化层构成，氧化膜的粘附性较好。     

Fe—Ni—Cr合金在H2S／H2／CO2混合气氛中的高温腐蚀

研究了铬含量相当，镍含量分别为１８ｗｔ％和３９ｗｔ％的两种Ｆｅ－Ｎｉ－Ｃｒ合金在Ｈ２Ｓ／Ｈ２／ＣＯ２混合气氛中于６００℃的腐蚀动力学产物层结构。镍含量不同使腐蚀产物结构上有差异；１８ｗｔ％Ｎｉ合金的外腐蚀层为ＦｅＳ，其下是ＦｅＣｒ２Ｓ４和Ｃｒ３Ｓ４；而３９ｗｔ％Ｎｉ合金的腐蚀产物外层是疏松多孔，呈黑色粉状的（Ｎｉ，Ｆｅ）Ｓ，其下也是ＦｅＣｒ２Ｓ４与Ｃｒ３Ｓ４；而３９ｗｔ％Ｎｉ合金的腐蚀产物外层是疏     

0Cr18Ni15Mo4不锈钢在烯硫酸介质中表面钝化膜研究

采用ＡＥＳ和ＸＰＳ表面分析技术，测量了０Ｃｒ１８Ｎｉ１５Ｍｏ４奥氏体不锈钢在２０％Ｈ２ＳＯ４和模拟湿法冶金铜电解液（２０％Ｈ２ＳＯ４＋３５ｇ／ＬＣｕ＾２＋）中表面膜的合金元素分布、组态和结构。实验表明表面钝化膜形成外层为氢氧化物和内层为氧化物的双层结构。在还原性稀硫酸中，钝化膜中形成以Ｍｏ（Ⅵ）和Ｃｒ＾３＋为主的含Ｎ氧化物、氢氧化物，当溶液中啬Ｃｕ＾２＋离子的去极化作用时，Ｍｏ元素的钝化作用受到抑     

电镀锌层表面黑变膜的研究

用ＳＥＭ、ＥＤＸ、ＸＲＤ、ＸＰＳ等技术分析了电镀锌层表面黑变膜的组成和结构。结果表明,黑变膜是锌的腐蚀作用及杂质Ｐｂ去极化作用的共同产物。它由ＺｎＯ、Ｚｎ５（ＣＯ３）２（ＯＨ）６及微量ＰｂＯ组成,膜表层Ｚｎ是以ＺｎＯ形态存在,而膜内层则以非化学计量化合物ＺｎＯ１－ｘ形态存在。并发现黑变膜是一种锌受腐蚀所形成的表面膜上产生的光干涉现象。     

Corrosion Behaviour of Zn and Zn Alloy Coatings in Alkaline Media

The corrosion behaviour of electrodeposited Zn, Zn-Co, Zn-Fe and Zn-Ni coatings without and with Chromate films was studied in alkaline solutions and mortar probes. DC polarization measurements were used for electrochemical characterization of the investigated samples, while AES XPS techniques were applied for the Chromate film analysis. The stability of the anodically formed oxide films on unchromated coatings appeared to be dependent on their composition. The oxide layer stability in Cl free NaOH solution was higher for Zn-Ni and Zn-Co alloys, while introduction of Cl ions caused lowering of stability especially for Zn-Ni coating. The detected corrosion current values implied that unchromated Zn alloys did not possess higher corrosion resistance in alkaline media containing Cl ions. Meanwhile, chromated Zn-Co coatings exhibited the beneficial effect of alloying for corrosion in alkaline solutions and concrete. A higher concentration of Cr(Vl) compounds in the passive Chromate layer of the alloyed sample may be the reason for its superior corrosion resistance.     

硼酸对镁合金达克罗涂层耐蚀性能的影响

目的提升镁合金的耐腐蚀性能。方法采用电化学测试、盐雾试验、XRD及SEM等方法,研究了不同硼酸添加量对AZ31镁合金达克罗涂层组织与耐蚀性能的影响,并分析其成膜机理。结果镁合金达克罗涂层主要由Zn、Mg、MgCrO_4、ZnO、MgO、Cr_2O_3、CrO_3组成,添加硼酸后,涂层中出现B_2O_3。MgCrO_4、MgO含量随着硼酸含量的增加而降低,而Cr_2O_3和CrO_3含量增加,并在硼酸加入量(质量分数)为2%的涂层中达到极限值。未添加硼酸的达克罗涂层表面存在微孔及微裂纹,添加2%硼酸的涂层的致密性能得到提高,当进一步增加硼酸含量时,涂层的致密性再次降低。添加2%硼酸涂层的腐蚀电流密度为5.068×10~(-5)A/cm~2,比未添加硼酸涂层时降低了1个数量级。涂层的电化学阻抗谱容抗弧半径和阻抗值,均在2%硼酸添加量时达到最大值,此时涂层耐蚀性能最好。结论硼酸具有促进成膜的作用,添加2%硼酸能够增加涂层的致密性,提高涂层的耐蚀性能。     

等离子体改性1Cr18Ni9Ti不锈钢钝化膜的耐蚀性

等离子体改性１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢钝化膜的耐蚀性雷明凯，袁力江，孔常静，张仲麟（大连理工大学大连１１６０２４）电子回族共振（ＥＣＲ）微波等离子体具有高电子密度和离化率，低放电粒子溅射率及无极放电设计等优点［１－２］，为金属钝化膜的改性提供了有效和...     

氮元素对2Cr13不锈钢CO2腐蚀产物膜结构和电化学性能的影响

利用高温高压釜进行2Cr13不锈钢的高温高压CO2腐蚀实验，用扫描电镜（SEM）和X射线光电子谱（XPS）分析腐蚀产物膜的形貌和成分，电化学交流阻抗谱测试腐蚀产物膜对2Cr13不锈钢电极过程影响，失重法评价两种2Cr13不锈钢CO2均匀腐蚀速率．结果表明：含氮钢的腐蚀产物膜结构比较疏松，腐蚀膜中的Cr2O3被CrN和Na3CrO4部分替代，并且含有较多的Fe3O4和α—FeOOH，其膜的电阻值比不含氮的2Cr13钢的小，腐蚀速率较大．     

Preparation and Corrosion Resistance of Silicate Passivation Film Formed on Galvanized Zn Coatings

In this paper,one kind of silicate passivation technics was reported and by which method silicate passivation film on galvanized Zn coatings with satisfactory property was got.Zn coatings were prepared by conventional plating technics.The solution composition and operating conditions of passivation are:sodium silicate 10-30 g/L,H2SO4 5 mL/L,HNO3 5 mL/L,H2O2 5-20 mL/L,pH 1.5-2.5,passivation time 5-30 s,temperature 25℃.The corrosion resistance of galvanized Zn coatings with different passivated technics were investigated by NSS corrosion test and compared with Zn coatings treated by Cr(VI)and Cr(III).The silicate passivation film can keep no rust for 72 h and obviously shows the best property.Surface morphologies of galvanized Zn coatings with different passivated method were got by metallurgical microscopy,and the silicate passivation film shows the most uniform surface,and has the least micro-hole.All the results show that silicate passivation technics can provide galvanized Zn coatings superior anti-corrosion performance and simultaneously avoid the pollution of chromium,so this technology has a wide application in future.     

Cl~-浓度对双相钢和镍基合金腐蚀速率的影响

针对H2S、CO2、Cl-同时存在的高温、高压腐蚀环境,选择22Cr、25Cr双相不锈钢和028铁-镍基合金、G3镍基合金进行对比试验,在其它条件相同的情况下(H2S/CO2分压、温度、液体流动等条件一致,仅Cl-浓度变化),分析Cl-含量对各种耐蚀合金管材发生均匀腐蚀与点蚀的腐蚀速率的影响。结果表明,在温度为160℃,CO2分压为4.13MPa,H2S分压为2.66MPa,流速为3m/s的条件下,随着Cl-浓度增加(25g/L、100g/L、120g/L、250g/L),UNS S32205和UNS S32750两种双相不锈钢的均匀腐蚀速率和局部腐蚀速率增加;028和G3两种镍基合金的均匀腐蚀速率变化不大,且无局部腐蚀发生。UNS S32205、UNS S32750双相不锈钢试样表面钝化膜的主要成分为Cr2O3和/或Cr(OH)3;028和G3镍基合金试样表面钝化膜的主要成分为NiO、Cr2O3和/或Cr(OH)3。     

Corrosion behavior of NiCr alloys in HCl-containing oxidation atmosphere at 700-800 ℃

Corrosion behaviors of pure Ni and three NiCr alloys were investigated in an HCl-containing oxidizing atmosphere at 700 ℃ and 800 ℃. All materials suffer from accelerated corrosion at both temperatures. NiCr alloys show an initial mass loss due to the formation of volatile CrCl3 and CrO2Cl2. Some chlorides are detected at the scale/substrate interface and many voids are also found there. NiCr alloys with higher chromium content have better corrosion resistance. However, Ni50Cr is inferior to Ni25Cr due to its two-phase structure, which makes it easy for chlorine to diffuse along grain boundary and to occur inner oxidation. The relevant corrosion mechanism was also discussed.     

Corrosion Behavior of Cu40Zn in Sulfide-Polluted 3.5% NaCl Solution

The corrosion behavior of a duplex-phase brass Cu40Zn in clean and sulfide-polluted 3.5% NaCl solutions was investigated by conducting electrochemical and gravimetric measurements. The corrosion product films were analyzed by scanning electron microscopy, energy-dispersive spectroscopy and x-ray diffraction. The presence of sulfide shifted the corrosion potential of Cu40Zn toward a more negative value by 100 mV and increased the mass loss rate by a factor of 1.257 compared with the result in the clean solution. The corrosion product film in the clean solution was thin and compact; it mainly consisted of oxides, such as ZnO and Cu₂O. By contrast, the film in the sulfide-polluted solution was thick and porous. It mainly contained sulfides and zinc hydroxide chloride (i.e., Zn₅(OH)₈Cl₂·H₂O). The presence of sulfide ions accelerated the corrosion damage of Cu40Zn by hindering the formation of protective oxides and promoting the formation of a defective film which consisted of sulfides and hydroxide chlorides.