Electric Pulse To Improve Billet Quality

Metal solidification structure is one of the most important factors that decide properties of metal. Essentially electric pulse technology is a new technology to control alloy solidification process by acting a special electric field in liquid metal. The effects and the significance of electric pulse on solidified structure of casting slab for continous casting process are described in this text. The defects of continuous casting slab and the methods to improve and refine the casting structure are summarized.In order to search the optimal parameter scope in the laboratory condition , taking HRB335 steel as object ,the three factors of the pulse current, frequency and acting time were considered together. The results showed that it was feasible to use the electric pulse treating on the metal solidification structure. The optimal parameters on the condition of laboratory were found as follows: the pulse current was about 100 A, the frequency was about 3 Hz and the acting time was about 60 s.On the fundamental of laboratory experiments,taking Q235steel,STB32steel as objects, the industrial trials above the slab crystallizer of Pan Steel were carried out., After eliminating effects of superheat and pulling rate , the effects of impulse current and pulse frequency on the slab qualities were examined.. In order to research the effects of electric impulse on slab solidified organization, the best electric impulse parameter that could improve slab qualities, three influences from electric impulse on equiax crystal rate, grain size as well as element segregation. were discussed .By detecting and analysing,it was found that the slab equiax crystal rate was increased, crystal grain was refined, element segregation was alleviated after exacting electric impulse. The optimal parameters on the condition of industry were obtained as follows: the pulse current was about 200 A, the frequency was about 5 Hz,which came to a prospective test objective.The results showed that it was feasible to use the electric pulse treating on the continuous casting,but the effect of the treating was changable with the different parameters of the electric pulse.