Method of continuous casting of cogged ingot

Abstract

The present invention discloses a continuous casting technology, which can greatly reduce defects of a cogged ingot of bloom continuous casting. A technical scheme of the present invention is: the continuous casting technology of the cogged ingot comprises double cooling of solidified shell, wherein the solidified shell goes through five shower cooling areas in sequence to be twice cooled. Cooling intensity in cooling direction of five shower cooling areas is as following: 151 to 1941 / (min is multiplied by m 2 ), 24 to 501 / (min is multiplied by m 2 ), 23 to 351 / (min is multiplied by m 2 ), 12 to 191 / (min is multiplied by m 2 ) and 8 to 111 / (min is multiplied by m 2 ). The present invention gradually reduces the cooling intensity of the solidified shell with the solidified shell thickening, thereby effectively reducing inside and outside difference in temperature of the solidified shell, decreasing heat stress of the solidified shell and reducing defects of the bloom continuous casting. The present invention is especially suitable for the cogged ingot of bloom continuous casting with a cross of 450mm multiplied 360mm that is made up of medium-carbon ferromanganese such as 35Mn2 and 37 Mn2.

Description

technical field [0001] The invention relates to a continuous casting method in the field of iron and steel metallurgy, in particular to a secondary cooling process in the continuous casting process of a bloom. Background technique [0002] At present, high-strength section steel, round steel, and seamless steel pipes, which have strict requirements on internal quality and compression ratio, mainly produce billets by continuous casting, and then roll the billets to obtain finished products. According to the cross-sectional shape of the billet, the billet can be divided into square billet, round billet and slab. In the continuous casting process, molten steel flows into the continuous casting machine from the steelmaking furnace, and is cooled for the first time in the crystallizer of the continuous casting machine, and is initially solidified into a billet shell with a certain thickness; the billet shell is continuously discharged from the mold The lower port is pulled out a...

AI Technical Summary

Problems solved by technology

For blooms with a cross-sectional size greater than 200mm×200mm, especially medium-carbon manganese steel billets with a cross-sectional size of 450mm×360mm, such as 35Mn2 tubular billet steel blooms with a cross-sectional size of 450mm×360mm, due to its cross-sectional The large size makes the temperature difference between the inside and outside of the slab large, and the thermal stress generated is also large, and the slab has a strong tendency to produce internal cracks; moreover, the thermal conductivity of medium-carbon manganese steel such as 35Mn2 and 37Mn2 is higher than that of low-carbon steel such as 20# steel. Poor, the slab is more sensitive to intermediate cracks

Therefore, for a square billet with a size larger than 200mm×200mm and poor thermal conductivity, using the existing continuous casting method, defects such as surface cracks and internal cracks in the billet are serious