| Products by the electroslag remelting (ESR) process have advantages of high purity, compact structure, homogeneous composition and clean surface, therefore electroslag remelting technology has been developed quickly in recent years. However, the consumable electrodes are required in the standard ESR operation and the efficiency of the process is low. The limit of ESR is broken through by the electroslag continuous casting with liquid metal (ESCC LM). The ESCC LM eliminates the economic problem brought by preparing and manufacturing electrodes during ESR and this eletroslag technology has the advantage of continuous casting promoting its efficiency. At present, the ESCC LM is immature and the practice data of the technology is lacking home and abroad. Sschemes (ESCC LM-I and ESCC LM-II) of the technical innovation are devised, and the research on numerical simulation and technical combining its characteristic is carried out in this paper.The design principle of slag used for ESCC LM is presented and the high electric resistance slags are desiged. The physical and chemical properties are measuresed by experiment or calculated by experiential formula. MgO replaces some CaO in the slag to enhance its ablity of water resistance.The ESCC LM mathematical model is established on the basis of electric field and heat convection equations. The designed technical schemes of ESCC LM-Ⅰand ESCC LM-Ⅱare simulated and analized by means of ANSYS software.The results of modeling ESCC LM-Ⅰ manifest the values of voltage, current density and joule heat are bigger around the slag bath, especially the part close to current conductive mould. The peak values appear in vicinity of insulation pad; the temperature field is lower in center part and higher around. The highest slag bath temperature value is1853℃and the peak value of melted matel bath depth is484mm when the efficient voltage and steel pouring temperature reaches45V and1590℃, respectively. The results of modeling ESCC LM-Ⅱ show that the shorter the distance from slag to electric conductive ring is, the greater the values of voltage, current density and joule heat are. The values of voltage, current density and joule heat reach the peak in contact part of slag bath and ring tip. A high temperature region appears in the slag bath under and inside the graphite ring. The maximum temperature of slag bath is2006℃and the maximum depth of matel bath564mm when the efficient volt and steel pouring temperature reaches30V and1590℃, respectively.Both of the schemes have the same aspects in pouring with liquid metal, refining through the reaction between slag and liquid metal, obtaining energy from heat generation of slag and casting continuously. The difference of the both process is that the ESCC LM-Ⅰ comes into being shallow hot metal bath and requires high performance of insulation material; ESCC LM-Ⅱ displays excellent power efficiency, and on the otherside, appears deeper metal pool.The influence of different technological parameters to ESCC LM-Ⅰ is analysed through simulation.The temperature range:1580～1600℃, efficient voltage:40-50V, slag depth:200～300mm, steel pouring speed:12～16mm·min-1ascertained by finite elements analysis will be reasonable.The ESCC LM industrial experiments are originated in the world. The surface quality of the ESCC LM solid ingot doesn’t meet expectation still. The macrostructure examination of the ingot shows that there is no shrinkage cavity, no flaw and no sufance coarsened grain size. The general porosity and the center porosity are both less than level1.5. The edge equiaxed grain zone ranges from24-33mm. Shown by macrostructure examination, the quality of the ESCC LM casting ingot performances better than the continuous casting one. |
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