| abstract |
Disclosed are a thin-strip continuous casting high hole expansion steel and a manufacturing method therefor. The chemical ingredients of the steel in percentages by weight are as follows: 0.01-0.05% of C, 0.2-0.6% of Si, 0.8-1.5% of Mn, ≤0.02% of P, ≤0.005% of S, ≤0.008% of N, <0.001% of Als, ≤0.0050% of Ca, 0.001-0.006% of B, >250 of Mn/S, 0.007-0.020% of total oxygen [O]T, and the balance is Fe and inevitable impurities, and same comprises one or both elements of 0.1-0.6% of Cu and 0.005-0.04% of Sn. In the present invention, the residual elements, such as Sn and Cu, in the scrap steel are used for smelting, and microalloy elements, such as B, are selectively added; the basicity of slag, the type and melting point of the inclusion in steel, the content of free oxygen in molten steel and the content of acid-soluble aluminum Als during the smelting process are controlled, and a strip is cast by means of twin-roll thin strip continuous casting, the strip then directly enters a lower closed chamber after leaving a crystallization roller and enters an online rolling mill for hot rolling in closed conditions, and after rolling, the strip steel is cooled by air atomization cooling and is finally coiled. |