Continuous casting process of steel grades such as bearing steel and the like

Abstract

A continuous casting process of steel grades such as bearing steel and the like comprises the following steps: (a) determining accurate temperature of molten steel among various flow numbers in a pouring basket; and (b) respectively working out flow rate of each flow of mould cooling water, casting blank casting speed corresponding to each flow of a mould and cooling water ratio of secondary cooling water at the secondary cooling zone of each flow of the mould according to the relation between the casting speed and molten steel temperature: when the casting speed of continuous casting billets increases or reduces by 0.10m/min, equivalent to temperature of the molten steel in the mould reduces or increases by 3.0 DEG C-6.0 DEG C. Compared with the prior art, the continuous casting process has the advantages of being capable of quickly discovering and finding out key factors for producing center line shrinkage and central porosity of the continuous casting billets of the steel grades such as the bearing steel and the like, being capable of timely proposing or taking measures, promoting timely and good improvement of related macro defects of the continuous casting billets of the steel grades such as the bearing steel and the like, improving macro quality of the continuous casting billets, and improving practical quality of the steel grades such as the bearing steel and the like, thus increasing economic benefit of manufacturers.

Description

technical field [0001] The invention relates to the field of steel production and manufacture, in particular to a continuous casting process for bearing steel and other steel types. Background technique [0002] The temperature control factor of the molten steel in the tundish of the continuous casting machine is the "steering wheel" for the normal operation of the entire continuous casting machine. The current continuous casting process of bearing steel and other steel types all adopts a temperature measurement of molten steel in a certain place in the tundish as the only basis for setting the casting speed of all flows in the tundish, ignoring the internal temperature of the tundish. The objective difference of molten steel temperature between each flow number. Cause the center shrinkage cavity and center porosity of the continuous casting slab (material). [0003] The same slab casting speed subjectively reduces the temperature of the molten steel in the middle flow in ...

AI Technical Summary

Problems solved by technology

[0003] The same slab casting speed subjectively reduces the temperature of the molten steel in the middle flow in the tundish, because the actual molten steel temperature here is relatively high, which objectively leads to the tendency of shrinkage cavity in the center of the continuous casting slab; at the same time, the same The casting speed subjectively increases the temperature of the molten steel at the edge flow number in the tundish. Since the actual temperature of the molten steel here is relatively low, the slower casting speed objectively leads to the deterioration of the fluidity of the molten steel here. The nozzle of the liquid is easily blocked, and the replacement of the nozzle will cause severe secondary oxidation of the molten steel and deteriorate the quality of the billet

In this way, sometimes it will even affect the overall quality of the whole furnace and the whole batch of continuous casting slabs

Moreover, the mold cooling water flow control for each flow rate and the secondary cooling water ratio water control in the secondary cooling section are the same, which violates the basic common sense of continuous casting that different cooling methods should be adopted for billets at different temperatures