Characterization of Corrosion Behavior of Irradiated X65 Low Carbon Steel in Aerobic and Unsaturated Gaomiaozi Bentonite  

作　　者：Canshuai Liu Jianqiu Wang Zhiming Zhang En-Hou Han Wei Liu Dong Liang Zhongtian Yang 

机构地区：[1]Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]China Institute for Radiation Protection

出　　处：《Acta Metallurgica Sinica(English Letters)》2019年第4期506-516,共11页金属学报（英文版）

基　　金：supported by Key Research Program of Frontier Sciences, Chinese Academy of Sciences (QYZDYSSWJSC012);the National Natural Science Foundation of China (No. 51771211);the National Key Research and Development Program of China (2017YFB0702100, 2016YFE0105200);Key Program of the Chinese Academy of Sciences (ZDRW-CN-2017-1)

摘　　要：2.98 kGy/h(1007 h) gamma irradiation and 90 ℃(2000 h) thermal aging were exerted to X65 grade low carbon steel buried in Gaomiaozi bentonite containing 17 wt% Beishan groundwater. The average corrosion rate of X65 low carbon steel was measured. The elemental and phase distribution on cross section was characterized by using electron probe micro-analysis, high-resolution X-ray diffraction, and micro-X-ray diffraction. The following conclusions can be made: the average aerobic corrosion rate of the carbon steel is(45.16 ± 1.53) μm/year. Taking the original surface as boundary, the corrosion scale is divided into an internal dense product layer(DPL) mainly composed of Fe_3O_4 with segregated FeCO_3 at the corrosion front and an external DPL mainly composed of Fe_3O_4 with segregated α-Fe_2O_3 and bentonite at some relics.Si, S, and Cl are concentrated at the corrosion front of the internal DPL, while Si and Al are concentrated at the external DPL.2.98 kGy/h(1007 h) gamma irradiation and 90 ℃(2000 h) thermal aging were exerted to X65 grade low carbon steel buried in Gaomiaozi bentonite containing 17 wt% Beishan groundwater. The average corrosion rate of X65 low carbon steel was measured. The elemental and phase distribution on cross section was characterized by using electron probe micro-analysis, high-resolution X-ray diffraction, and micro-X-ray diffraction. The following conclusions can be made: the average aerobic corrosion rate of the carbon steel is(45.16 ± 1.53) μm/year. Taking the original surface as boundary, the corrosion scale is divided into an internal dense product layer(DPL) mainly composed of Fe_3O_4 with segregated FeCO_3 at the corrosion front and an external DPL mainly composed of Fe_3O_4 with segregated α-Fe_2O_3 and bentonite at some relics.Si, S, and Cl are concentrated at the corrosion front of the internal DPL, while Si and Al are concentrated at the external DPL.

关 键 词：Low carbon steel Corrosion rate Phase distribution ELEMENTAL concentration 

分 类 号：TG[金属学及工艺]