Simulation For Heat Transfer Behavior Of Steel And Slag Interface In Slab Mold With Argon Blowing

Injection of argon gas in a mold aims to prevent nozzle clogging and the argonbubbles in the mold contribute to the homogenization of the composition andtemperature of the molten steel. However, the floatation of argon gas into the fluid moldpowder disturbs the interface between liquid steel and mold powder, which thendefinitely has an influence on the heat transfer behavior,the melting of mold powderand the well-proportion of initial solidified shell. Therefore, it is of great importance tostudy the heat transfer behavior of the interface between liquid steel and mold powder ina mold with argon blowing. for the optimization of argon blowing process parametersand the improvement of the quality of billet.This paper investigates the influence of molten steel flow and argon blowingparameters on the fluctuation of free surface in the slab mold by establishing a0.6:1(model: prototype) down-scale physical model and adopts mathematical model forcoupling computation of the material transfer and heat transfer of molten steel. It isfound that:(1) Based on the water model experience on slab mold with argon blowing and thecomputational results of mathematical model, it is stated that the fluctuation range ofthe interface between liquid steel and mold powder by decreasing the casting speed andincreasing the depth of submerged entry nozzle (SEN) and the port angle of nozzle.(2) At a lower casting speed，the distribution of temperature of the interfacebetween liquid steel and mold powder focus on two places: around the nozzle and nearthe narrow wall. With the increase of the quantity of argon blowing, there is a slightchange of temperature and temperature center near the narrow wall while thetemperature around the nozzle presents a variation from increasing to decreasing and theplace of temperature center gradually approaches the nozzle.(3) With casting speed increased from0.8m/min to1.2m/min, both of the twoplaces of temperature center moves to the narrow wall but the change of their temperature is different.The temperature of the former gradually decrease while that ofthe latter gradually increase; with casting speed increased from1.2m/min to1.4m/min,there is an addition of a third temperature center with a lower value near the narrow wall;at a casting speed of1.6m/min, a region with high temperature appears as a result ofslag entrapment.(4) with the increase of the depth of SEN,there is a slight change of the region oftemperature center and temperature value though the place of temperature center aroundthe nozzle shows a moving tendency to the narrow wall and temperature value increase;(5) with the increase of the port angle of nozzle，there is also a slight change oftemperature and temperature center around the nozzle though temperature increases andthe place of temperature center shows a moving tendency to the nozzle; the temperaturenear the narrow wall slightly increase and the place of temperature center has anobvious movement to the nozzle with the port angle of the lateral hole increased to18o.