Corrosion mechanism research and microstructure analysis of Baosteel No��3 blast furnace hearth
Xun-fu Wang1,2,Qi-jie Zhai1
1 School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China 2 Ironmaking Plant of Baoshan Iron & Steel Co., Ltd., Shanghai 200941, China
Corrosion mechanism research and microstructure analysis of Baosteel No��3 blast furnace hearth
Xun-fu Wang1,2,Qi-jie Zhai1
1 School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China 2 Ironmaking Plant of Baoshan Iron & Steel Co., Ltd., Shanghai 200941, China
ժҪ Baosteel No��3 blast furnace hearth was divided into tuyere area, taphole area, taphole upper side wall and taphole lower side wall according to different working situations. Through chemical composition analysis, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry and other means, chemical composition and microstructure of different parts of hearth carbon brick were analyzed and markedly different corrosion mechanisms of these areas were found. Zn element in form of ZnO mainly deposited on the hot side of carbon brick. There was no obvious evidence that Zn permeates into carbon bricks and erodes them. Except for taphole area, K, Na, and Fe contents from hot side to cold side gradually rise and fall, resulting in the decrease of apparent porosity, the increase of density and the higher thermal conductivity compared with those of new carbon brick. The higher content of Fe in carbon brick leads to more serious erosion because Fe has greatly changed the physical properties of carbon brick. In the taphole area, the contents of Si and Al present obvious concentration gradient because of the mechanical souring of molten iron and slag. The SiO2 and Al2O3 particles that have different expansion factors with carbon brick damaged the carbon substrate because of temperature fluctuation. The graphitized carbon found on H4 where is the most serious corrosion site means that the carbon brick ever directly contacts with molten iron.
Abstract��Baosteel No��3 blast furnace hearth was divided into tuyere area, taphole area, taphole upper side wall and taphole lower side wall according to different working situations. Through chemical composition analysis, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry and other means, chemical composition and microstructure of different parts of hearth carbon brick were analyzed and markedly different corrosion mechanisms of these areas were found. Zn element in form of ZnO mainly deposited on the hot side of carbon brick. There was no obvious evidence that Zn permeates into carbon bricks and erodes them. Except for taphole area, K, Na, and Fe contents from hot side to cold side gradually rise and fall, resulting in the decrease of apparent porosity, the increase of density and the higher thermal conductivity compared with those of new carbon brick. The higher content of Fe in carbon brick leads to more serious erosion because Fe has greatly changed the physical properties of carbon brick. In the taphole area, the contents of Si and Al present obvious concentration gradient because of the mechanical souring of molten iron and slag. The SiO2 and Al2O3 particles that have different expansion factors with carbon brick damaged the carbon substrate because of temperature fluctuation. The graphitized carbon found on H4 where is the most serious corrosion site means that the carbon brick ever directly contacts with molten iron.
Xun-fu Wang,,Qi-jie Zhai. Corrosion mechanism research and microstructure analysis of Baosteel No��3 blast furnace hearth[J]. �й������ڿ���, 2017, 24(10): 1016-1022.
Xun-fu Wang,,Qi-jie Zhai. Corrosion mechanism research and microstructure analysis of Baosteel No��3 blast furnace hearth. Chinese Journal of Iron and Steel, 2017, 24(10): 1016-1022.
Zhang shourong, Yu zhongjie,the BF campaign life technologies in Wuhan iron and steel company,Metallurgical Industry Press,2009,Beijing,p.195.
[2]
Wang xunfu,Liu zhenjun,Sun guojun,Investigation and Mechanism Research on Hearth Corrosion of No. 2 BF in Baosteel,iron and steel,44(2009),No.9,p.7.
[3]
Lin chengcheng, Xiang zhongyong, Design feature and operation practice for Baosteel No.3 blast furnace long campaign life, annual academic meeting of iron-making, China Metal Institute, 2102,p.149~155.
[4]
Zhu renliang, Xiang zhongyong, Profile design and operation of No.3 blast furnace in Baosteel, Ironmaking, (31)2012,No.1,p.12~16.
[5]
Zhang longlai, Lin chengcheng, Discusstion on stability control technology for large-scale blast furnaces, Baosteel Technology, 2011,No.2,p.1-5.
[6]
Jiao Kexin, Zhang Jianliang, Zuo Haibin, Zhao yongan,Composition and Formation Mechanism of Viscous Layers in Blast Furnace Hearth, Journal of Northeastern University(Natural Science),35(2014),No.7,p.988.
[7]
Shinotake A��Nakamura H��Yadoumaru N�� Investigation of blast furnace hearth sidewall erosion by core sample analysis and consideration of campaign operation,ISIJ International��(43)2003��No. 3,p. 321��
[8]
Wang Baohai��Xie Minghui��Che Yuman,Investigation on damage of Angang��s new No.3 blast furnace hearth and bottom,Ironmaking��(31)2012,No. 6,p.19.
[9]
Song Musen,Yu Zhongjie, Xiong Yafei,Investigation on the lining erosion of No.5 BF in Wuhan Iron and Steel Corporation, Ironmaking,(27)2008,No. 4,p.1-10��
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