Laser Scanning Confocal (Direct Reduced Iron Direction) Microscope LEXT Application in Steel Metallurgy Industry

  • Yi Man, Xiaomo Yu, Yu Zeng

Abstract

With the continuous development of the steel metallurgy industry, direct reduction technology and direct reduced iron production have developed rapidly. However, research and analysis are currently not comprehensive enough and research is limited. In order to solve the problem that the observation is not clear enough and the analysis is not comprehensive enough, this paper studies the application analysis of laser scanning confocal microscope LEXT in the steel industry. The laser scanning confocal microscope LEXT, ray diffractometer, scanning electron microscope and image analysis software are used to reduce the pellets. The mechanism of process microstructure evolution was studied. The reduction kinetics of magnetite composite binder pellets and magnetite oxidized pellets were studied. The isothermal reduction kinetics study showed that the reduction temperature ranged from 800°C to 1050°C. The composite binder pellet reduction reaction was controlled by interfacial chemical reaction and internal diffusion mixing. The variation of the strength of the two magnetite pellets during the reduction process was studied. The results showed that the pellets were reduced during the composite binder pellet reduction process. The compressive strength through area (compressive strength less than 500 N/piece) lasts only 30 min, and the compressive strength “low valley area” during the oxidized pellet reduction process lasts for 70 min. The results show that the difference in the internal crack generation and propagation mechanism of the pellet determines the difference in strength. During the reduction process, the cracks in the composite binder pellets are mainly caused by the phase transformation stress, and the crack morphology is dominated by concentric cracks.

Published
2019-06-21