316L不锈钢表面电镀Pd-Ni合金膜在模拟维纶醛化液中的耐蚀性能  

Corrosion resistance of electro- plated Pd- Ni alloy film on 316L stainless steel surface in simulated aldehyde condensation solution

作　　者：吴昌霖 鞠鹏飞[1] 左禹[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029

出　　处：《石油化工腐蚀与防护》2013年第5期1-5,共5页Corrosion & Protection In Petrochemical Industry

基　　金：国家科技支撑计划(2012BAE04B01)的资助项目

摘　　要：维纶生产中的醛化液主要含硫酸、硫酸钠和甲醛,不锈钢在高温醛化液中腐蚀速率很高。通过电镀法在316L不锈钢表面生成了Pd质量分数约为60%的Pd-Ni合金膜层,镀层均匀致密,厚度约2μm,硬度达到540 HV,与基体结合力良好。在80℃的模拟醛化液中,316L不锈钢表面电镀Pd-Ni合金膜后腐蚀速率降低了3个数量级。极化曲线测试表明,电镀Pd-Ni镀层有效促进了不锈钢基体的钝化,316L不锈钢在模拟醛化液中的自腐蚀电位从-0.3 V提高到+0.2 V,低频阻抗值提高了三个数量级。当模拟维纶醛化液中的氯离子质量分数在200μg/g以下时,镀层仍然能够保持良好的耐蚀性;随着氯离子质量分数的提高,试样的自腐蚀电位逐渐负移,腐蚀速率增大。该方法可以改善不锈钢设备在高温醛化液中的耐蚀性。The corrosion rates of stainless steels are very high in high - temperature aldehyde condensation solution because the aldehyde condensation solution mainly contains sulfuric acid, sodium sulfate and formaldehyde. A palladium - - nickel film with 60 wt% Pd was electroplated on 316L stainless steel surface. The plated film, which was compact and whose thickness was 2 p^m and hardness was 540 HV, had a good adhesion to the substrate metal. In the simulated aldehyde condensation solution at 80~C, the corrosion rate of the 316L stainless steel plated with Pd - Ni film was reduced by 3 orders of magnitude. The polarization curves show that the Pd - Ni film has effectively promoted the passivation of the stainless steel substrate. The self corrosion potential of 316L stainless steel in simulated aldehyde condensation solution was raised to 0.2 VscE from -0.3 VscE. The low-frequency resistance was increased by 3 order of magnitude. When chloride concentration in simulated aldehyde condensation solution was below 200 ppm, the Pd - Ni film showed a good corrosion resistance. With increasing chloride concentration in the solution, the self- corrosion potential of sample moved toward negative and the corrosion rate rose. This method can be used to improve corrosion resistance of stainless steels in aldehyde condensation solution.

关 键 词：不锈钢 钯-镍镀层 醛化液 电镀 耐蚀性 

分 类 号：TG171[金属学及工艺—金属表面处理]