Effect Of Magnetic Field On Crystal Structure And Orientation During Iron Precipitation

In this paper,the solid state reduction of wustite under the action of magnetic field is taken as the research object,and the influence law of 1.02T steady magnetic field on the crystal structure and growth orientation of the material is analyzed.It also reveals the mechanism of the magnetic field from a micro perspective.Place the dense wustite sample in a magnetic field reduction furnace?B=1.02T?,and perform low-temperature solid-state reduction at a reduction temperature of 800?and a mixed atmosphere of 75%CO-25%CO₂.After reduction,the metallization rate calculation and SEM and EDS detection are used to characterize the solid-state reduction rate and morphology of the wustite under the action of magnetic field;Through XRD analysis and crystal structure calculation,the influence of the steady magnetic field on the crystal structure and growth orientation of the phase during the solid state reduction of the wustite was revealed.In the process of CO reduction of wustite,the application of a 1.02T steady magnetic field increases the lattice constant of the wustite and reduces the lattice constant of the product metal iron.Therefore,the pore structure of the metallic iron surface is strengthened,so that the pores increase and the pore diameter becomes larger.The magnetic field reduces the Fe-O bonding energy of the wustite and increases the bond energy of the metallic iron.This change in energy is conducive to promoting the further generation of metallic iron by the wustite.The magnetic field increases the diffraction intensity of the metallic iron?110?and?200?crystal planes.The calculation of the degree of orientation shows that the magnetic field promotes the growth of metallic iron in the<100>crystal orientation.The solid-state reduction process of wustite consists of the rearrangement of wustite and the growth of metal iron nuclei.Since the magnetic anisotropy of the<100>crystal direction is the lowest,the final rearrangement of the surface of the wustite and the growth of metallic iron form a stable arrangement with the easy magnetization axis<100>parallel to the external magnetic field direction.