本文選題：土壤降阻劑　切入點：緩蝕　出處：《東北電力大學》2017年碩士論文　論文類型：學位論文

【摘要】：變、配電站接地系統(tǒng)常采用填充降阻劑的方法降低接地網接地電阻以達到接地設計要求,但研究發(fā)現降阻劑的使用會引起接地電極的腐蝕問題。本課題采用我國產量豐富的膨潤土材料作為降阻劑基材,添加常用緩蝕劑鉬酸鈉與六偏磷酸鈉,制備具有緩蝕作用的土壤降阻劑,以解決上述問題。同時,在該土壤降阻劑中添加優(yōu)良的導電材料石墨,降低土壤降阻劑的電阻率,優(yōu)化其降阻性能。主要研究內容如下:根據膨潤土優(yōu)良的吸附性能,通過溶液浸漬法,將鉬酸鈉及六偏磷酸鈉與膨潤土復合,制備緩蝕型土壤降阻劑。采用SEM分析方法對降阻劑進行形貌表征。以Q235A碳鋼為工作電極,通過Tafel曲線及交流阻抗譜研究了反應時間、反應溫度及緩蝕劑含量的變化對碳鋼電極在該降阻劑中腐蝕情況的影響。結果表明:溶液浸漬法制備緩蝕型土壤降阻劑的最佳制備條件為水與膨潤土的質量比為10:1、鉬酸鈉添加量為5.0 wt.%、六偏磷酸鈉添加量為2.0 wt.%、水浴溫度為25℃,反應時間為6.0 h。在該條件下制備所得降阻劑中,Q235A碳鋼電極的腐蝕電位為-0.563 V,腐蝕電流為0.00647μA。為找出更簡便的制備方法,通過物理球磨法將鉬酸鈉及六偏磷酸鈉與膨潤土復合,制備緩蝕型土壤降阻劑。以碳鋼為工作電極,通過Tafel曲線及交流阻抗譜研究了球磨時間及緩蝕劑含量的變化對碳鋼電極在該降阻劑中腐蝕情況的影響。結果表明:采用物理球磨法制備土壤降阻劑的最佳制備條件為球磨時間30 min,六偏磷酸鈉添加量為1.6 wt.%,鉬酸鈉添加量為4.0 wt.%。該條件下制備所得土壤降阻劑中,Q235A碳鋼工作電極的腐蝕電位為-0.599 V,腐蝕電流為0.0129μA。為優(yōu)化降阻劑的導電性能,在降阻劑中添加石墨,考察不同石墨添加量對降阻劑性能的影響。結果表明:添加石墨會在一定程度上增大土壤降阻劑對Q235A碳鋼的腐蝕性,加速碳鋼電極表面的溶解速率,且當石墨添加量過大時會嚴重破壞降阻劑的吸水率。但添加石墨可以大大降低降阻劑的電阻率,當石墨添加量為15 wt.%時,土壤降阻劑的電阻率降低至5?·m以下,達到《接地降阻劑》中對接地土壤降阻劑電阻率的要求。最后,通過腐蝕失重實驗、SEM表面形貌表征及電化學測試等方法探討該緩蝕型土壤降阻劑的緩蝕機理。結果表明,碳鋼試片在該緩蝕型土壤降阻劑中浸泡后,表面會附著一層均勻致密的保護層,從而減緩碳鋼材料的腐蝕速率。
[Abstract]:In order to meet the requirements of grounding design, the grounding system of distribution station often uses the method of filling resistance reducing agent to reduce the grounding resistance of grounding grid. However, it was found that the use of resistance reducer would cause corrosion of grounding electrode. In this paper, the abundant bentonite material was used as the base material of resistance reducing agent, and the common corrosion inhibitors, sodium molybdate and sodium hexametaphosphate, were added. In order to solve the above problems, a soil resistance inhibitor with inhibition effect was prepared. At the same time, the resistivity of the soil resistance reducer was reduced by adding good conductive material graphite to the soil resistance reducer. The main contents are as follows: according to the excellent adsorption property of bentonite, sodium molybdate and sodium hexametaphosphate were combined with bentonite by solution impregnation. The corrosion inhibitor was prepared. The morphology of the inhibitor was characterized by SEM. The reaction time was studied by Tafel curve and AC impedance spectroscopy using Q235A carbon steel as working electrode. The effect of reaction temperature and corrosion inhibitor content on the corrosion of carbon steel electrode in the inhibitor was studied. The results showed that the optimum conditions for preparing corrosion inhibitor of soil by solution impregnation were as follows: mass ratio of water to bentonite was: 1. 10: 1, sodium molybdate 5.0 wt., sodium hexametaphosphate 2.0 wt., water bath temperature 25 鈩，

本文編號：1614735