摘要:
在Q345钢试样上喷涂无机富锌底漆、环氧云铁中间漆和丙烯酸聚氨酯面漆复合涂层,采用盐雾试验测试涂层的耐蚀性能,结合扫描电镜(SEM)观察腐蚀形貌,并计算腐蚀速率,采用电子探针分析技术(EPMA)对腐蚀介质的渗透原理进行了研究。结果表明:盐雾试验后,涂覆复合涂层试样的腐蚀速率仅为基材的6%左右,且表面形貌整体质量较好,仅预制划痕处腐蚀程度加重,腐蚀产物呈絮状,微观结构疏松,但腐蚀后涂层与基体宏观附着良好;Cl-可以穿透底漆到达金属基体,对金属产生腐蚀,而中间漆和面漆能够有效地阻止腐蚀溶液的渗透。
Abstract:
The composite coating on Q345 steel surface was prepared by spraying. The corrosion resistance of the composite coating was tested by salt spray test,the corrosion morphologies was observed by using the SEM,the corrosion rate was calculated,the penetration principle of corrosive media was analyzed by using the electron probe microanalysis( EPMA). The results show that the corrosion rate of Q345 steel with composite coating reduces to approximately 6% and the corrosion resistance has improved. But the corrosion near the scratch was serious. The microstructure of the corrosion product is flocculent loose,but coating can stick firmly to the matrix after the corrosion. Corrosion occurs when Cl-penetrates the primer coating to the matrix. The intermediate coating and top of the coating could prohibit the permeation corrosive fluid,retarding the corrosion.
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