Steel for controlled rolling and controlled cooling platform and production method thereof

The invention relates to steel used for controlled rolling and cooling offshore platform, and a production method thereof. The invention belongs to the technical field of low-alloy high-strength steel. The steel was produced through slab continuous casting and TMCP processes after steel making and refining. The components of the slab are as follows: 0.05 percent to 0.09 percent of C, 1.20 percent to 1.60 percent of Mn, 0.20 percent to 0.50 percent of Si, 0.03 percent to 0.05 percent of Nb, 0.010 percent to 0.020 percent of Ti, 0.03 percent to 0.06 percent of V, equal to or less than 0.005 percent of S, 0.020 percent to 0.040 percent of Als, equal to or less than 0.015 percent of P, and the rest are Fe and impurities. Molten steel which is smelt by the component is cast into the slab which is 220mm to 250mm thick; the ingot is put into a slap heating furnace to be heated and rolled when being discharged. The initial billet temperature for rough rolling is 1060 DEG C to 1160 DEG C, the initial billet temperature for fine rolling is 840 DEG C to 940 DEG C, and the finishing temperature is 780 DEG C to 820 DEG C; the thickness of the rolled steel sheet is 10mm to 60mm. The starting cooling temperature is 760 DEG C to 810 DEG C; the finishing cooling temperature is 550 DEG C to 650 DEG C; the cooling speed is 10 DEG C/s to 17 DEG C/s. The production method has the advantages of simplified procedures and cost saving.