Experimental investigation on ablation characteristics of coated and uncoated steel under 30/80 μs impulse current  

作　　者：Mingqiu DAI Yakun LIU Zhengcai FU Juan LIU Xiaolei BI 戴明秋;刘亚坤;傅正财;刘娟;毕晓蕾(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education,Department of Electrical and Engineering,Shanghai Jiao Tong University,Shanghai 200030,People’s Republic of China;SINOPEC Researching Institute of Safety Engineering,Qingdao 266000,People’s Republic of China)

机构地区：[1]Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education,Department of Electrical and Engineering,Shanghai Jiao Tong University,Shanghai 200030,People’s Republic of China [2]SINOPEC Researching Institute of Safety Engineering,Qingdao 266000,People’s Republic of China

出　　处：《Plasma Science and Technology》2019年第7期123-134,共12页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China (No. 51577117)

摘　　要：The ablation tests on coated and uncoated Q235 B steel sheets were conducted under 30/80 μs impulse current simulating the lightning first return stroke current, aimed at further understanding the ablation characteristics of steel and investigating the impact of anti-corrosion coating on these characteristics. Ablation characteristics were investigated through the macroscopic morphology and x-ray diffraction patterns on the surface of damaged zones, the microstructure and micro Vickers hardness on the cross-section of damaged zones, and the maximum rear-face temperature of sample sheets. It can be concluded that the ablation areas of uncoated sheet consist of the melted layer and the heat-affect layer. These ablation areas include not only the area ablated directly by the arc root, of which the depth is deeper, but also the area forming due to the splashing of molten steel, of which the depth is shallower and decreases when the area’s distance from the arc attachment point increases. For coated sheet, coating materials have decomposed and evaporated forming an ablation pit on the sheet surface, in which the steel surface is exposed, and zinc filler of coating primer has infused into the exposed surface. The ablation diameter of uncoated sheet relates to the amplitude of the 30/80 μs impulse current in quadratic function, while for coated sheet, the relation is linear. In general, under the 30/80 μs impulse current, the coating can decrease the energy injected from the arc to the steel sheet and reduce the melting and splashing of steel. As a result, the ablation severity of uncoated sheet is severer than that of coated sheet.The ablation tests on coated and uncoated Q235 B steel sheets were conducted under 30/80 μs impulse current simulating the lightning first return stroke current, aimed at further understanding the ablation characteristics of steel and investigating the impact of anti-corrosion coating on these characteristics. Ablation characteristics were investigated through the macroscopic morphology and x-ray diffraction patterns on the surface of damaged zones, the microstructure and micro Vickers hardness on the cross-section of damaged zones, and the maximum rear-face temperature of sample sheets. It can be concluded that the ablation areas of uncoated sheet consist of the melted layer and the heat-affect layer. These ablation areas include not only the area ablated directly by the arc root, of which the depth is deeper, but also the area forming due to the splashing of molten steel, of which the depth is shallower and decreases when the area’s distance from the arc attachment point increases. For coated sheet, coating materials have decomposed and evaporated forming an ablation pit on the sheet surface, in which the steel surface is exposed, and zinc filler of coating primer has infused into the exposed surface. The ablation diameter of uncoated sheet relates to the amplitude of the 30/80 μs impulse current in quadratic function, while for coated sheet, the relation is linear. In general, under the 30/80 μs impulse current, the coating can decrease the energy injected from the arc to the steel sheet and reduce the melting and splashing of steel. As a result, the ablation severity of uncoated sheet is severer than that of coated sheet.

关 键 词：arc ablation effect ANTI-CORROSION coating LIGHTNING first return stroke CURRENT 30/80 μs IMPULSE CURRENT Q235B STEEL microstructure x-ray diffraction 

分 类 号：TG142.1[一般工业技术—材料科学与工程]