高硅铬铁高压直流接地极腐蚀监测技术与焦炭层填充试验研究

目的 掌握高压直流接地极服役过程中的运行参数及腐蚀状况，包括接地极运行时周边土壤温湿度和馈电元件的腐蚀速率与腐蚀总量等。方法 采用精密电阻探针腐蚀监测技术以及失重法，对比研究加和不加焦炭填包料的高硅铬铁直流接地极在强直流试验过程中，土壤温升与接地极腐蚀情况。结果 基于电阻探针技术，可以准确测量通电过程中馈电元件的腐蚀总量和腐蚀速率。相反，受电化学极化原理限制，电化学监测技术难以对通电状态下的馈电元件腐蚀进行测量。结论 填充的焦炭包覆层能有效延缓高硅铬铁直流腐蚀，使腐蚀速率下降96%。这主要归功于高硅铬铁表面包覆焦炭层后，电解反应从高硅铬铁/土壤层界面过渡到焦炭层/土壤界面，因而对高硅铬铁起到较好的保护作用。

Corrosion Monitoring Technology of High Silicon Ferrochrome High-voltage DC Grounding Electrode and Experimental Study on Coke Layer Filling

This paperaims tograsp the operation parameters and corrosion status of HVDC grounding electrode during service, including the temperature and humidity of surrounding soil during the operation of grounding electrode, the corrosion rate and total corrosion amount of feed elements, etc. Using the precision resistance probe corrosion monitoring technology and weight loss method, the soil temperature rise and grounding electrode corrosion of high silicon ferrochrome DC grounding electrode with and without coke filler during the strong DC test were compared. Based on the resistance probe technology, the total corrosion amount and corrosion rate of the feed element can be accurately measured during the power on process. On the contrary, due to the limitation of the electrochemical polarization principle, the electrochemical monitoring technology is difficult to measure the corrosion of the feed element under the power on state. The filled coke coating can effectively delay the DC corrosion of high silicon ferrochrome and reduce the corrosion rate by 96%. This is mainly attributed to the fact that after the high silicon ferrochrome surface is coated with coke layer, the electrolytic reaction transits from the high silicon ferrochrome/soil layer interface to the coke layer/soil interface, thus playing a better role in protecting the high silicon ferrochrome.