Flow Control to a T-shaped Five-strand Tundish for Its Overall Enhanced Metallurgical Effects with an Approachable Identical Products Quality

Abstract

In response to the frequent problem of inconsistent quality of billet castings and their rolled products from each strand by a five-strand tundish, the flow field in tundish is optimized by presenting new flow control devices and conducting isothermal physical modelling along with numerical simulation. The results show that the dead volume fraction of the optimized case A6 is reduced from 27.74% to 19%, the stagnation time is prolonged from 12 s to 35 s, and the flow dynamic consistency for each strand is improved as well. In the subsequent industry production tests, the temperature difference of molten steel at the outlet of each strand is reduced to 1~5 ℃.The maximum difference of the as-cast equiaxed crystal rate among five strands is reduced from 5.67% to 2.7%, and the consistency of carbon segregation index is also improved with a basically identical appearance through the billet cross section. The maximum differences in oxygen and nitrogen contents for the rolled products of all strands are 2.7 ppm and 5.7 ppm respectively, which are lower than 5.0 ppm and 13.8 ppm before tundish optimization. The yield strength of rolled products is stabilized with much less divergence as compared to the products with the original tundish. Thus, it is believed that the reasonable flow field optimization to a multi-strand tundish not only will have a well-known positive impact on its tranditional metallurgical effect, but also may bring out an approaching identical steel quality from the same caster as we expected.

Structural optimisation of three-strand asymmetric tundish for super large round bloom continuous casting

“…In contrast, adding flow control devices offers a direct and efficient method that involves minimal changes to refractory materials, resulting in lower costs and improved metallurgical outcomes in the tundish. 12,13 Flow control devices in tundish, such as turbulence inhibitors, retaining walls and gas-permeable barriers, are critical for refining molten steel. 14,15 Lin et al 16 employed fluid-structure interaction simulations to examine the forces on turbulence inhibitors at casting onset, identifying height and brim width as vital to stress distribution.…”

“…In contrast, adding flow control devices offers a direct and efficient method that involves minimal changes to refractory materials, resulting in lower costs and improved metallurgical outcomes in the tundish. 12,13…”

Research on the Relative Placement Angle of the Induction Heater and the Channel in a Four-Channel Induction-Heating Tundish

“…In order to optimize the effectiveness of induction-heating tundishes, scholars have made many efforts and attempts. Tang et al [ 18 ] optimized the flow pattern of molten steel by adding flow control devices such as retaining walls and dams in the discharging chambers of multi-strand IH tundishes. This approach improved the consistency of each strand and reduced the dead ratio in multi-strand tundishes.…”

Numerical and Physical Modeling of Liquid Steel Asymmetric Behavior during Non-Isothermal Conditions in a Two-Strand Slab Tundish—“Butterfly Effect”

“…One of the essential components of a continuous casting machine is a tundish, with which additional metallurgic treatments can be successfully realized, specifically refining, microalloying, and molten steel reheating [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Whereas the tundish is a flow reactor, a unique thermo-hydrodynamic system forms inside its working space, as a function of the tundish's shape, capacity, number of outlets, and installation of flow control devices or non-standard equipment, e.g., a vacuum chamber, annular porous permeable brick with a swirl block, swirling chamber, or multi-port ladle shroud [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. In addition, the hydrodynamic system in the tundish is modified by the temperature gradient generated by the cooling of molten steel during the casting process, the inflow of a hotter or colder batch of steel into the tundish from the ladle, or the steel-reheating zones in the tundish [31][32][33][34][35][36][37][38][39][40].…”