20Cr13不锈钢表面聚四氟乙烯涂层的制备及性能

Preparation and properties of polytetrafluoroethylene coating on 20Cr13 stainless steel

[目的]无油工艺螺杆压缩机转子常用的材质为20Cr13马氏体不锈钢,具有一定的耐酸、碱腐蚀性能,但工作环境为湿硫化氢或含较高浓度的氯离子时,会发生一定程度的腐蚀。[方法]配制了几种含聚四氟乙烯(PTFE)的涂料并喷涂在20Cr13钢试样表面,经干燥、高温固化后得到聚四氟乙烯涂层。对涂层的硬度、附着力、耐磨性及耐湿硫化氢和氯离子腐蚀等性能进行了测试。[结果]聚四氟乙烯+环氧树脂+聚酰胺-酰亚胺(PAI)体系的填充改性+共混改性的涂层最为均匀致密,磨耗低,在3.5%NaCl溶液中的低频阻抗模值最大,综合性能最优。[结论]在20Cr13钢表面喷涂经过适当改性的PTFE涂层,可以提高其耐蚀性及耐磨性。

[Introduction]The rotors of oil-free process screw compressors are usually made of martensitic stainless steel 20Cr13,which has good resistance to acid and alkali,but will undergo certain corrosion when the working environment is wet hydrogen sulfide or contains high concentration of chloride ions.[Method]Several kinds of polytetrafluoroethylene(PTFE)containing paints were prepared and sprayed on the surface of 20Cr13 steel,forming PTFE coatings after drying and high-temperature curing.The hardness,adhesion strength,wear resistance,and anticorrosion performance in wet hydrogen sulfide and chloride ion environments of these coatings were tested.[Result]The coating prepared by blending PTFE,epoxy resin,and polyamide-imide(PAI)with some fillers as the modifiers was uniform,compact,and had a low wear loss and a large low-frequency impedance magnitude in 3.5%NaCl solution,showing good comprehensive performance.[Conclusion]The suitably modified PTFE coating can improve the corrosion and wear resistance of 20Cr13 steel.