摘要:本课题的目的在于研究出一种环境低毒,并且能取代毒性高的751价铬钝化工艺的三价铬钝化工艺。通过单因素试验,对钝化液中的各个组成成分,以及钝化的工艺条件进行探索和研究,得到一个最适合的三价铬彩色钝化液配方工艺。该工艺主要成成膜物是Cr2(SO4)3•6H2O,含量为8g/L;配位剂为丙二酸,含量为5g/L;氧化剂是NaNO3,含量为5g/L;活化金属离子选NiSO4•6H2O,用量为1.2g/L;阴离子促进剂NaCl,含量0.5g/L;pH值为1.6;钝化温度为25℃;钝化时间为80s。该工艺能够得到一层致密的,光亮细致的三价铬彩色钝化膜。对最佳配方工艺进行中性盐雾实验、附着力实验、乙酸铅点滴实验,结果表明,耐盐雾时间可达78小时,乙酸铅点滴实验出现黑点时间可达74秒,附着力良好。23680
毕业论文关键字:镀锌;三价铬;彩色钝化;
Study on Trivalent Chromium Colorful Passivation Technology for Potassium chloride zinc plating
Abstract: The purpose of this project is to develop a low-toxicity of trivalent chromium passivation process on the environment, to be used to replace the high toxicity of hexavalent chromium passivation process. By single-factor experiment and orthogonal, passivation solution composition and passivation process carry out exploration and research, has been one of the best formula of trivalent chromium color passivation technology. The process of major film is Cr2(SO4)3•6H2O, content 8g/L; complex agent for malonate, content 5g/L; oxidants is NaNO3, content 5g/L; activating metal ions selected NiSO4•6H2O, the dosage of 1.2g/L; anions promoter NaCl, 0.5g/L; pH 1.6; passive temperature 25℃; passive time of 80s. The process can be a dense layer of passive film on three price chromium colored passivation film and looks bright and detailed. Neutral salt spray test, the best formulation process experiment of adhesion test, lead-acid, showed that salt-fog resistance of up to 78 hours, lead-acid drop experiment appears black spots of up to 74 seconds, good adhesion.
Keywords:galvanization;trivalent chromium;Color Passivation
目 录
1 绪论 1
1.1 钝化的用途及分类 1
1.2 钝化液各组分的作用 2
1.3 三价铬离子彩色钝化 3
1.4 三价铬彩色钝化原理 4
1.3 课题国内外研究的概况、水平 5
1.4 三价铬离子彩色钝化的发展趋向 6
2 工艺研究部分 7
2.1 试样准备 7
2.2 氯化钾镀锌 7
2.3 三价铬彩色钝化液钝化 8
2.4 镀层质量检验 8
3 实验研究 10
3.1 实验仪器、试剂、材料 10
3.1.1 主要仪器和材料 10
3.1.2 主要试剂 10
3.2 镀锌层的制备 10
3.2.1 镀锌液的配制 10
3.2.2 试片镀锌 10
3.3 基础钝化配方及工艺参数的确定 11
3.3.1 三价铬盐的选择 11
3.3.2 配位剂的选择 12
3.3.3 氧化剂的选择 13
3.3.4 金属活化离子的选择及其含量对钝化膜性能的影响 13
3.3.5 阴离子促进剂的选择 14
3.3.6 钝化操作条件的确定 14
4 试验结果与讨论 16 镀锌层三价铬离子彩色钝化液研究:http://www.751com.cn/huaxue/lunwen_16864.html