N80钢表面陶瓷涂层的制备及耐酸蚀性研究

采用热化学反应方法在N80钢基体表面制备了陶瓷涂层。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、体视显微镜和划痕仪对涂层的物相结构、组织形貌和膜基界面结合力进行了研究,利用失重法在20%的质量分数盐酸溶液中测试了涂层的耐蚀性能。结果表明:在600℃固化温度下,以SiO2粉体和SiO2、Al2O3、MgO等两类不同骨料制得的陶瓷涂层中,前者无新相生成,涂层与基体界面结合力24 N;后者有新相MgAl2O4生成,且涂层比较致密,涂层与基体界面结合力约40 N。以水玻璃作粘结剂的复合氧化物陶瓷涂层的表面致密度、平整性均优于以磷酸氢铝作粘结剂的涂层。酸腐蚀测试表明,以水玻璃作粘结剂的复合氧化物陶瓷涂层的平均腐蚀速率约为基体的1/2左右。

Research on the Preparation and Acid-resistance Property of Ceramic Coating on N80 Steel Surface

The ceramic coatings were prepared on N80 steels by thermo-chemical reaction method.The phases,the surface morphology and the bond force of the coating were observed and analyzed by XRD,SEM,stereomicroscope and scratch tester.The acid resistance of samples in 20wt% HCl solution was studied by the weight loss method.The results show that,at 600 ℃,no new phases were found in ceramic coating with SiO2 as aggregates and coating-substrate adhesion(critical load) is 24 N,while new phase of MgAl2O4 appeared in the ceramic coatings with SiO2,Al2O3,MgO,etc as aggregates.This kind of ceramic coatings are dense and coating-substrate adhesion(critical load) is 40 N or so.The surface flatness and density of composite oxide ceramic coatings with sodium metasilicatenonahydrate adhesive were better than that of coatings with aluminum hydrogen phosphate adhesive.Acid corrosion tests reveals that the average corrosion rate of composite oxide ceramic coatings with Sodium metasilicatenonahydrate adhesive is around 1/2 that of steel substrate.