| Oxide dispersion strengthened steel(ODS steel)is an emerging steel for the nuclear industry with high temperature strength?excellent radiation resistance and corrosion resistance.The traditional powder metallurgy production method has obvious problems in cost and production efficiency.Therefore,a new idea of casting ODS steel is proposed,that is,the inert gas is used to spray the nanoparticles into the molten steel ? using high frequency electromagnetic oscillation the resulting cavitation effect prevents the agglomeration of the nanoparticles ? electromagnetic stirring to evenly distribute the nanoparticles.Based on the above-mentioned technical ideas,this paper studies the following aspects of the gas-liquid two-phase behavior in the reactor,the flow of metal liquid and the behavior of bubbles under different modes of magnetic fields:1.The method of water simulation was used to study the water bubble generation process,the bubble diameter,the trajectory,the speed of the movement and the amount of air blowing during the bottom blowing of argon.The diameter is 0.3? 1.5 mm,and the blowing volume is in the range of 20?120 ml/min.The bubble diameter increases with the increase of the blowing volume and the blowing hole.Under the experimental conditions,the terminal velocity u T of the bubble is about 250 mm/s,and u T decreases first and then stabilizes with the increase of the bubble diameter;at a blowing volume of 20 ml/min,the blowing position in the liquid metal is directly above the liquid level and the positive speed is 30 mm/min.In the near-wall position,the maximum negative flow rate is-20 mm/min and the downward flow is reversed.When the side hole is blown,the blowing volume is increased to 80 ml/min and 120 ml/min.2.The influence of magnetic field parameters on liquid metal flow were studied under traveling,rotating,modulated traveling and modulated rotating magnetic field.The results show that under the condition of a traveling wave magnetic field with an excitation current I = 100?300 A and a frequency f = 2?8 Hz,a flow in the same direction as the magnetic field is formed at a wall position near the magnetic field,and a position at the center of the container is generated.The opposite reflux,and the metal liquid flow is the strongest under the parameters of 300 A/8 Hz;under the rotating magnetic field of I = 50?100 A,f = 4?8 Hz,the metal liquid forms two structures in the axial direction with similar directions opposite And the intensity increases with the increase of the current frequency;the flow of the metal liquid is strengthened under the modulation magnetic field,and the flow is the strongest at Tm=10 s under the condition of 100 A/2 Hz under the modulated traveling magnetic field,The flow intensity does not change with Tm under conditions of 200 A and 2/4 Hz;it is observed that the depth of the rotating vortex is suppressed under the conditions of 75 A and 4 Hz.3.The effect of bottom-driven argon bubble on molten metal flow was investigated with the application of traveling magnetic field(TMF)and rotating magnetic field(RMF).The experimental results show that: When the traveling wave magnetic fields with parameters of 100 A/8 Hz and 20 ml/min are superimposed with the bottom blowing gas,the internal flow of the metal liquid is strengthened.When the upward and downward magnetic fields are applied,r/R=0.56.There will be frequent changes in the flow direction;at 50 A/2 Hz and 75 A/4 Hz and 20 ml/min rotating magnetic field and bottom blowing parameters under the conditions of metal flow is enhanced secondary flow structure,75 A/4 Hz magnetic field parameters superimposed with 80 ml/min blowing volume flow structure changes,Is the superimposed mode of secondary flow and bubble-driven flow. |
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