The Research Of Secondary Cooling Water Distribution Technology Of Thick Rectangular Billet Continuous Caster

The process of continuous casting is to put the molten steel cast into billet close to theend product.This transcendental idea became a reality has experienced one hundred yearsof exploration, finally in the1970s began to large-scale application. Development to today,continuous casting technology already quite mature, but the traditional production of thinslab has not meet the needs of the projects, especially bridges, tunnels and other industryurgently need some steel with large cross section size. In the study to improve the quantityand quality of casting billet,in the meantime, the research of thick slab continuous casterhas become the top priority. Comply with this requirement, in this paper, calculating andanalyzing related parameters of the700mm×1500mm rectangular billet of heavy sectioncontinuous caster. Due to the secondary cooling of continuous casting has importantinfluence on the production and quality of continuous casting machine, so formulatingreasonable secondary cooling system of continuous caster to let slab quickly and evenlycooling forming on the basis of satisfying metallurgical principles, it becomes the mainresearch content of this article.First, analyze and calculate the overall parameters, thermal physical parameters andthe secondary cooling water of thick rectangular billet, to facilitate the use of follow-upstudies;Then, the secondary cooling zone of caster has been reasonablely segment,preliminarily determine the total secondary cooling water and paragraphs of cooling water,by the every length of secondary cooling, consider process elements of secondary coolingwater distribution, combine with high temperature mechanical properties of steel andmetallurgical principles to determine the surface temperature model of the secondarycooling zone;Again, this article is based on the calculation method of numerical simulation,establish two-dimensional heat transfer finite element model of special thick slabsolidification, let the target surface temperature distribution as the boundary conditions ofthe solidification and heat-transfer model in the secondary cooling zone of slab, according to the heat-transfer model, inversely calculate heat transfer coefficient distribution of thesecondary cooling zone, simulating and analyzing the solidification process of secondarycooling zone paragraphs, to get the slab thickness and temperature distribution ofparagraphs, comparing to the target to validate the rationality of the design of thesecondary cooling segment, and further grasp the shell growth characteristics, accordingto the relation between the heat transfer coefficient and flow density to calculate the actualwater distribution of secondary cooling zone, comparing with the initial value, thesecondary cooling of paragraphs total water volume and water allocation has beenoptimized;Finally, after understanding the influence of the cooling characteristic and thearrangement of the nozzle effect slab cooling, the equipments needed for achieving thecooling effect are studied, that is to say the nozzle selection and reasonable layout, and athree-dimensional coupled thermo-mechanical model is established for stress and strainsimulation, get the crack index distribution law of slab in secondary cooling zone anddrum belly deformation condition, compared with the limiting stress value of the steel anddrum belly limiting value, the feasibility of the nozzle selection and layout is validated.