| In this paper,the flux coating method and magnetic levitation melting-negative pressure suction casting method is used to fabricate corrosion-resistant iron-based amorphous composite samples with excellent mechanical properties and soft magnetic properties from industrial raw materials.Effects of alloy structure and room temperature mechanical properties,and the effects of alloying of different kinds of rare earth elements on the electrochemical corrosion properties and room temperature magnetic properties of amorphous composites were studied.The results showed that the using industrial-grade Q235 steel and Fe-Cr alloys,by adding a coating agent and adjusting the alkalinity R?R=0,2,3,4,5,6?to optimize the removal of impurity elements in industrial raw materials,was investigates firstly.In the as-cast Fe-15Mn-5Si-14Cr-0.2C Fe-based amorphous composite,the crystalline phases are consist of the undercooled Austenite phase(CFe15.1)and Ferrite phase?Fe-Cr?.After compressive loading,the Austenite undergoes martensitic phase transformation,which enhances the toughness and improves the work hardening degree.Thus,the Fe-based bulk metallic glass composites exhibits excellent room temperature comprehensive mechanical properties.With the increase of the alkalinity of the coating agent,the elastic modulus,plastic strain,and breaking strength of the amorphous composites tend to increase first and then decrease.When R=4?that is,CaO:Fe2O3:SiO2=4:5:1?,the fracture strength of the amorphous composite material is up to 5777.2 MPa,and the compressive plasticity is 56.45%.Based on Fe-15Mn-5Si-14Cr-0.2C alloy system,single rare earth or mixed rare earth?Ce,Dy,Ce and Dy mixed rare earth?were added for micro-alloying.And the role of microstructure optimization,as well as the effect on alloy corrosion performance were studied.At room temperature in a 1mol/L HCL solution,the electrochemical corrosion behavior of Fe-15Mn-5Si-14Cr-0.2C fabricated from the industrial raw materials shows that the corrosion resistance is significantly better than that of 304 stainless steel.Due to the distortion effect caused by the large size difference of rare earth atoms and the redistribution of solutes caused by the addition of rare earth elements,the rare earth element compounds are enriched on the alloy surface.The protective layer of rare earth compounds formed,which improves the corrosion resistance of the substrate.The alloy obtained by adding the rare earth element Ce shows the best corrosion resistance,and its self-corrosion potential is-0.16205V,and the polarization resistance is up to 9.57742×108?·cm2.In the study of the electrochemical corrosion behavior of 1mol/L NaOH solution,it shows that the corrosion resistance is better than that in acidic and chloride ion environments.And the self-corrosion potential and self-corrosion current density,and the polarization resistance values are-0.1839V,1.745×10-8A·cm-2,7.1574×108?·cm2,respectively.Doping with different rare earth elements?Ce,Dy,Ce and Dy mixed rare earths?,the role of single rare earth or mixed rare earths in impurity purification and microstructure optimization,and the soft magnetic properties of Fe-based amorphous composites under different conditions to characterize the changes of saturation magnetization and coercivity,were studied.After adding different rare earth elements to the Fe-15Mn-5Si-14Cr-0.2C alloy system,the coercivity of the alloy shows a downward trend,while the saturation magnetization of the alloy increases significantly,and the alloy system shows good soft magnetic properties.The change tendency of the residual magnetization is consistent with the change of coercive force.The residual magnetization of Ce added alloy is only 13.57 emu.And the lowest coercivity of Fe-15Mn-5Si-14Cr-0.2C-1.0Ce alloy is 10.306emu.The rare earth element is a paramagnetic element at room temperature.The addition of RE element reduces the Curie temperature and anisotropy constant K1 of the ferroalloy.The magnetic crystal anisotropy reduces the energy density of the magnetic domain wall and reduces the resistance of the domain wall displacement. |
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