【作者】 李现涛；

【导师】 魏雨；

【作者基本信息】 河北师范大学 ， 物理化学， 2008， 硕士

【摘要】 磷化技术是当前采用较多的钢铁表面处理技术,在涂装工业中,由于锌盐磷化能够显著增加复合涂层的耐久性和使用寿命而被广泛应用。但大多数正在使用的磷化工艺处理温度较高,在磷化处理过的排出物中含有大量的沉渣,废油等,不仅造成了经济上的损失,而且主要因为大多数使用的磷化液中含有产生有毒气体的促进剂,造成对人体的危害。因此开发常温节能、无毒低污染的磷化工艺己成为当今磷化工艺的主要研究方向。本文就是在此背景下通过对氯酸钾、钼酸钠、对硝基苯磺酸钠（SNBS）等几种促进剂的筛选,确定钼酸钠为本磷化配方的主促进剂;同时确定基础磷化液的主要成膜物质为H3PO4和ZnO,辅助促进剂为HNO₃和Ni（NO₃）₂,其它添加剂有柠檬酸、OP乳化剂、NaF和Cu（NO₃）₂;通过正交试验法,对基础磷化液做耐蚀性正交试验分析和膜重正交试验分析,得到了钼酸钠常温磷化液的基础配方。基础配方为:H3PO4:30mL/L;ZnO:15g/L;硝酸:3.5mL/L;OP乳化剂:1mL/L;Na2MoO4:3g/L;Ni（NO₃）₂:4g/L;柠檬酸:1.0g/L;NaF:1.0g/L;Cu（NO₃）₂:0.05g/L;对所得磷化液基础配方做进一步研究,对钼酸钠、硝酸镍、柠檬酸、氟化钠和硝酸铜做单因素实验分析,对不同磷化时间、不同磷化温度对磷化膜性能的影响进行研究,得到了本磷化液的最优配方。最优配方为:H3PO4:30mL/L;ZnO:15g/L;硝酸:3.5mL/L;OP乳化剂:1mL/L;Na2MoO4:3g/L;Ni（NO₃）₂:4g/L;柠檬酸:1.5g/L;NaF:1.0g/L;Cu（NO₃）₂:0.05g/L;磷化温度:15～35℃;磷化时间:20min。通过硫酸铜点滴实验、氯化钠浸泡实验、膜重实验等对最优配方所得磷化膜做了性能测试;通过扫描电镜和X——射线能谱等物理检测技术研究了磷化膜的微观结构和元素组成;通过极化曲线的测量,研究了磷化膜的耐腐蚀性能;同时研究了超声波对磷化过程的影响;对磷化液的使用寿命和沉渣量做了初步计算。实验结果表明:本磷化液所得磷化膜膜层均匀、致密;硫酸铜点滴时间大于130秒,3%NaC1浸泡实验超过3小时,均超过国家标准;磷化膜的膜重为1.7～2.0g/m2,膜重在轻量级范围内;扫描电镜分析磷化膜微观结晶呈颗粒状;X——射线能谱分析结果显示磷化膜主要由Fe、P、Zn、Mo等元素组成;对比试件磷化前后的极化曲线,结果表明磷化后其自腐蚀电位变大,交换电流密度变小,耐腐蚀性增强;超声波对本磷化液的使用效果不理想;本磷化液的使用寿命经初步计算为0.3m2/L;沉渣量为0.3g/L。为本磷化工艺的推广应用提供了有用的数据,并给以后常温磷化配方的研究提供了借鉴。本文对钼酸钠常温磷化液中各组分的作用机理以及对磷化膜性能的影响做了初步探讨。更多还原

【Abstract】 Phosphating technology is one of the most widely used surface treatment for steel nowadays. In coating projects, Zn-Phos is widely used because it prolongs the service life of the coating noticeably. But in the most phosphating technics, the higher phosphating temperature, sediment and waste oil caused economical loss, and the toxic fumes which the phosphating soluting send out is harm to human health. So developing room temperature energy-conservation, nonpoisonous and low pollution phosphating craft has already become the main research direction now.Under this background, In this disquisition Na2MoO4 has been chosen as the main accelerant of the phosphating solution through comparison of effect of different accelerant （KClO₃, Na2MoO4 and SNBS）; The phosphating solution includes the main film forming matter （H3PO4, ZnO）, the main accelerant （Na2MoO4）, the accessory accelerant （HNO₃, Ni（NO₃）₂） and other additives （Emulsifier OP,Citric acid,NaF and Cu（NO₃）₂）; And this disquisition educes the basic solution through orthogonal experiments. It is as follow: H3PO4: 30mL/L; ZnO: 15g/L; HNO₃: 3.5mL/L; Emulsifier OP: 1mL/L; Na2MoO4: 3g/L; Ni（NO₃）₂: 4g/L; Citric acid: 1.0g/L; NaF: 1.0g/L; Cu（NO₃）₂: 0.05g/L.By analysing effect of single content （Na2MoO4, Ni（NO₃）₂, Citric acid, NaF and Cu（NO₃）₂） on corrosion resistance, effect of phosphating process and temperature, the best formula of the phosphating solution has been obtained. It is as follow: H3PO4: 30mL/L; ZnO: 15g/L; HNO₃: 3.5mL/L; Emulsifier OP: 1mL/L; Na2MoO4: 3g/L; Ni（NO₃）₂: 4g/L; Citric acid: 1.5g/L; NaF: 1.0g/L; Cu（NO₃）₂: 0.05g/L; Temperature: 15～35℃; Time: 20min。In this disquisition the corrosion resistance of phosphate coatings and the weight of phosphate coatings has been studied. SEM, X-rays energy spectrum etc. physical detective means had been used to observe the microstructure and elements content. By means of the measurement of the polarization curve, the phosphate coatings performance has been studied. And the effect of ultrasonic phosphating has been studied in this disquisition. The result shows: The phosphate coatings is even and compact; The dropping test of CuSO4 is more than 130s; 3% of the NaC1 soaks for 3 hours there is no rusty spot appear; The coatings weight is 1.7～2.0g/m2; The microstructure is granule-shaped by means of SEM; The element of the phosphate coatings includes Fe, P, Zn and Mo etc. The life-span of this phosphate solution is calculated for 0.3m2/L tentatively; The sediment is 0.3g/L; testing of the adhesion of the coatings has been carried out. It offered the basis for popularization and application of the phosphating technology and supplied references for the room-temperature phosphate research.The effect of the single content of this phosphating solution on the phosphate coatings performance has been studied in this disquisition.更多还原