Diffusion of carbon and titanium in γ -iron in a magnetic field and a magnetic field gradient

Structural control of Fe-based alloys through diffusional solid/solid phase transformations in a high magnetic field

“…However, it is very difficult to explain the microscopic mechanism of elongation because the growth rate depends on several factors, such as the γ /α phase boundary energy, the chemical driving force for the ferrite transformation, the demagnetization effect and the diffusion of carbon. The effects of a magnetic field on carbon diffusivity have been reported by Nakamichi et al [45] and Ohtsuka and Hao [46] and they both found that carbon diffusivity is retarded by a magnetic field, but they did not find any anisotropy of diffusivity. Koyama and Onodera [47] have modeled the structural change and carbon distribution for the lath martensite to austenite transformation in a magnetic field using the phase-field method.…”

“…Shimotomai [67] showed that the hardness of pearlite in steel increases when it is transformed in a magnetic field gradient. Nakamichi et al [45] reported that the diffusion of carbon in γ is enhanced in a magnetic field gradient when carbon atoms move in the direction with a higher magnetic field and retarded when an opposite magnetic field gradient is applied. Ono et al [34] determined the susceptibility of γ and α by measuring the magnetic force in a gradient magnetic field and obtained a time-temperaturetransformation (TTT) diagram for Fe-C alloys in a magnetic field.…”

Effect of a High Magnetic Field on Carbon Diffusion in γ-Iron

“…Pokoev et al 3,4) measured the diffusivity of nickel in -Fe and Fe-1.94%Si alloy and the magnetic effect on diffusivity were not monotonic as a function of applied magnetic field. Nakamichi et al 5) studied the effects of magnetic field and magnetic field gradient on the diffusion of carbon and titanium in -Fe and found that the carbon diffusion in -Fe was retarded by the application of a 6 T magnetic field. However, the diffusion of carbon in -Fe can be enhanced in a magnetic field gradient when carbon atoms move towards the direction with a higher magnetic field strength.…”

Metallurgical Characterization of API X65 Steel Joint Welded by MIG Welding Process with Axial Magnetic Field

“…It is known that the application of magnetic fields during the welding process improved the mechanical and corrosion properties of stainless steels [18][19][20][21][22][23][24] , aluminum alloys 25,26 and other steels [27][28][29] and alloys [30][31][32] . While high magnetic fields have been employed to modify solid phase transformations 24,29 , magnetic fields in the order of a few mT are used during arc welding in order to modify the grain structure of the weld bead 22,23,25,27 .…”

“…While high magnetic fields have been employed to modify solid phase transformations 24,29 , magnetic fields in the order of a few mT are used during arc welding in order to modify the grain structure of the weld bead 22,23,25,27 . In principle, an external magnetic field applied to the weld pool induces electromagnetic stirring and changes the convective patterns within the weld pool.…”