Provided is a continuous casting method of steel that prevents surface cracking simultaneously with ensuring the internal quality of slabs obtained by continuous casting at a higher speed by using a vertical liquid bending type continuous casting machine even if the slabs are extra-thick slabs.
A continuous casting method of steel according to the present invention is a continuous casting method of steel of continuously casting a slab by using a vertical liquid bending type continuous casting machine, in which when performing continuous casting while, by using an in-mold electromagnetic stirring device, applying an alternating-current moving magnetic field that moves in a width direction of a mold to molten steel inside the mold, inducing a swirling flow in the molten steel, and stirring the molten steel, a travel speed of the alternating-current moving magnetic field that is calculated by Formula (1) below is 0.20 to 1.50 m/s. Here, in Formula (1), U is the travel speed (m/s) of the alternating-current moving magnetic field, τ is a distance (m) between magnetic poles of a coil of the in-mold electromagnetic stirring device, and f is a frequency (Hz) of an electric current that is applied to the coil of the in-mold electromagnetic stirring device. U = 2 τf