接地网用导电防腐蚀涂层研究

Epoxy Based Conductive Anti-corrosion Coatings for Grounding Grid

采用物理混合的方法在接地网用Q235碳钢表面制备环氧树脂基导电防腐蚀涂层,研究了颜基比(PBR)对涂层性能的影响,确定了最佳颜基比。通过电化学阻抗技术测试了以最佳PBR制备的导电防腐蚀涂层对Q235碳钢在土壤中的防护行为,采用SEM技术分析了涂层的微观结构,并测试了涂层的电气性能。结果表明,Q235碳钢在土壤中发生严重腐蚀,E44环氧树脂清漆涂层防护作用有限,而导电防腐蚀涂层对Q235碳钢在土壤中具有优异的防护性能。涂层的体积电阻率和表面接触电阻分别为0.65Ω·cm和8.72Ω/cm^2。涂层经1 k A大电流冲击20次后,电阻率变化为5.95%,在10 A工频电流作用5次后涂层电阻率变化为11.09%,经冲击电流和工频电流作用后涂层完好,未发现剥落、烧蚀和裂纹等破坏。

Epoxy based conductive anti-corrosion coatings were prepared on the surface of ground- ing grid Q235 carbon steel with graphite, carbon fiber andalurninum tripolyphosphateas pigments. The influence of the pigment/binder ratio （PBR） on the properties of the coatings was investigated such as the morphology and the electric conductivity of the coatings as well the corrosion behavior of Q235 carbon steel coated by coatings with an optimal PBR by immersion in salt solutions and burying in a selected soil from Shenyang test site. The results indicated that after buried in the soil, the bare Q235 steel suffered from serious corrosion and bubbles occurred on the E44 lacquer coat- ing on the steel, in the contrast, the coatings with the optimal PBR showed excellent protectiveness for the steel even after buried for up to 1000 h in the soil. The volume resistivity and surface con- tact resistivity of the coatings are 0.65 ~＂ cm and 8.72 ~2/cm2 respectively. The coatings exhibited excellent with standing capacity to high current impulse, such as their electrical resistance de- creased by 5.95% and 11.09% for the ones suffered from a high current impulse of 1 kA for 20 times and a power frequency current of 10 A for 5 times respectively, while the surface of the coat- ings maintained unchanged without any destruction.