Abstract:In the process of continuous casting of ferritic stainless steel, the use of box-type electromagnetic stirring alone has problems such as unstable control of the ratio of equiaxed grains in the macrostructure and white bright bands caused by the stirring intensity. In order to improve the macrostructure of ferritic stainless steel, the application of combined electromagnetic stirring in ferritic stainless steel was carried out. Under the condition of industrial test, the effects of three stirring modes, including single box type, single roller type and box and roller combined type on the equiaxed crystal ratio and macrostructure of the ferritic stainless steels of 410, 430, 441 were analyzed. The results show that neither the single box type nor the single roller type can stably control the equiaxed grain ratio of the ferritic stainless steel. The box-type electromagnetic stirring is applied to the upper section of the second cooling or the roller-type electromagnetic stirring is separately applied to the lower section of the second cooling, and the proportion of equiaxed crystals is below 50%. Adopt box type and roller type combined electromagnetic stirring, under the condition of higher casting speed (CCM1), the parameters of the combined electromagnetic stirring are optimized. The stirring parameter of the box type is 1 210 A、2.7 Hz and the roller type is 350 A、8 Hz, which can stably control the ratio of equiaxed crystals to more than 60%, and at the same time can eliminate the secondary columnar crystals to obtain an ideal macrostructure. Under the condition of lower casting speed (CCM8), combined electromagnetic stirring parameters of the box stirring is 1 200 A、3.5 Hz and roll stirring is 380 A、8 Hz, the white light band defect was significantly improved.
Barna M, Javurek M, Wimmer P. Numeric simulation of the steel flow in a slab caster with a box-type electromagnetic stirrer[J].Steel Res Int, 2020, 91(11):2000067.