| Fe-Mn-Al-C series low-density steel has become a research hotspot at home and abroad due to its high plasticity,and is expected to become an alternative material system for automotive light weighting.And its high Al characteristics make it a candidate material system for preparing high-temperature anti-oxidation and electrochemical corrosion com-ponents.In this paper,the high-manganese high-alumina Fe-Mn-Al-1C low-density steels containing three components Mn27Al10Ni3,Mn27Al11Ni3 and Mn27Al9Si2Ni3 were designed from the viewpoint of Al content regulation and Al generation from Si.High-temperature oxidation corrosion and electrochemical corrosion behavior were studied.The mechanism provides the experimental basis and theoretical basis for expanding the application fields of high-manganese and high-alumina Fe-Mn-Al-C series low density steels.The results of high-temperature oxidation of Mn27Al10Ni3 and Mn27Al11Ni3 based on Al content indicate that the high temperature oxidation kinetic curves of the two steels follow the parabolic law.The oxide film mainly consists of Al2O3,Fe3O4,Fe2O3,Mn3O4,and Mn2O3 phases from the inside to the outside.During the oxidation process,the oxides of Al element are enriched on the surface of the matrix and form a continuous oxide film.With the increase of temperature,the oxides formed by the Al element increase on the sur-face of the matrix.The increase of Al content accelerates the filling rate of holes in the ox-ide layer,increases the density and adhesion of the oxide layer,and improves the high temperature oxidation resistance of the material.The results of high-temperature oxidation of Mn27Al11Ni3 and Mn27Al9Si2Ni3based on Si generation Al showed that the high temperature oxidation kinetic curves of the two steels follow the parabolic law.The oxide film mainly consists of Al2O3,Fe3O4,Fe2O3,Mn3O4,and Mn2O3 phases from the inside to the outside.By substituting 2wt%of Si for2wt%of Al element,Mn27Al9Si2Ni3 exhibited good oxidation resistance.The addition of Si element increases the density and adhesion of the oxide layer,reduces the probability of holes and microcracks on the surface of the oxide layer,and increases the oxidation re-sistance of the material.In addition,Si is preferentially oxidized on the surface of the sub-strate to form a dense oxide film,and the temperature is increased,the oxide is always en-riched on the surface of the substrate,and the degree of enrichment increases.The results of electrochemical corrosion studies of two high-manganese and high-aluminum low-density steels Mn27Al11Ni3 and Mn27Al9Si2Ni3 based on Si genera-tion Al show that:In corrosion of 3.5wt%NaCl solution,the corrosion current density of low-density steel decreases from 4.11×10-6 A·cm-2 to 1.06×10-6 A·cm-2 with the introduc-tion of Si,while low density The pitting potential of the steel also shifts positively by 0.01V,and significantly improves the ability of low density steels to resist Cl-erosion.In the corrosion of 1mol Na2SO4 solution,the corrosion current density of low density steel de-creases from 1.86×10-6 A·cm-2 to 1.95×10-6 A·cm-2 with the introduction of Si,and the breakdown potential is also shifted.0.0738V makes the low density steel more resistant to SO42-erosion.Compared with the traditional 304 stainless steel,these two materials have a certain gap between the resistance to Cl-and SO42-erosion and the traditional stainless steel. |
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