Production method for realizing continuous casting with low superheat degree

Abstract

The invention belongs to the technical field of steelmaking and continuous casting, and specifically relates to a production method for realizing continuous casting with a low superheat degree. Moltensteel is cleanly smelted and cast in a tundish and a continuous casting machine, the temperature is reduced by adding a cold steel wire in the tundish, so that the superheat degree of the molten steel is stably controlled between 5 DEG C and 15 DEG C, the low magnification class C qualification rate of a continuous casting blank obtained reaches 80% or above, the equiaxed crystal area is expandedto 30-60%, and the columnar crystal area is reduced to 70% or below. The problem of large change in the pouring superheat degree between a furnace and a furnace caused by the unstable production rhythm of molten steel in the traditional process, the fluctuation of a pouring temperature and other factors is solved, stable low superheat degree pouring is achieved, and the stability of continuous casting pulling rate is ensured; and the production method for realizing continuous casting with the low superheat degree has obvious effects on improving the low-magnification quality of the continuouscasting blank, reducing the central segregation of the continuous casting blank in the thickness direction, and expanding the equiaxed crystal ratio of the continuous casting blank, especially for the low-magnification structure improvement of the extra-thick continuous casting blank of 300mm or above.

Description

Technical field [0001] The invention belongs to the technical field of steelmaking and continuous casting, and specifically relates to a production method for realizing continuous casting with low superheat. Background technique [0002] The low quality of continuous casting slab is one of the most critical factors that determine the flaw detection quality and performance uniformity of rolled steel sheets. Especially thick slab continuous casting slabs, the continuous casting slabs are prone to macroscopic defects such as coarse columnar crystals, central segregation, and core inclusions. These defects are difficult to eliminate in subsequent heating and rolling processes. The quality of steel plate inspections , Z-direction performance, and thickness direction performance uniformity have a greater impact. At the same time, the higher the content of alloying elements, the thicker the thickness of the continuous casting slab, the worse the quality of the continuous casting slab, ...

AI Technical Summary

Problems solved by technology

[0003] At present, the main measures to realize continuous casting with low superheat in China include light reduction of continuous casting slabs, electromagnetic stirring and other technologies. These technologies have achieved certain effects on improving low-fold quality, but the effect is not obvious for extra-thick continuous casting slabs above 300mm , restricting the technical development and large-scale application of continuous casting slabs to produce extra-thick plates

[0004] In industrial production practice, low-superheat pouring has a significant effect on improving the low-fold quality of continuous casting slabs. However, due to steelmaking low-superheat pouring, the operation level and production rhythm control are extremely high. Improper control may easily lead to clogging, drainage, and downflow of the ladle nozzle. Slag, continuous casting slab casting speed reduction and other problems, it is difficult to promote large-scale industrial production

At present, in order to ensure the stability and safety of production, the superheat degree of pouring molten steel for continuous casting slabs can generally only be controlled between 15-30°C, and it is difficult to further reduce the superheat degree

Images