Manufacturing process for
corrosion-resistant and low-temperature-resistant continuous cast steel billets for
wind power, characterized in that it comprises the following steps: S1, steel production in an electric furnace:
oxygen is blown into the electric furnace for
decarburization and
phosphorus removal; after
slag formation,
slag is blocked and steel is tapped to obtain a steel melt; S2, low-temperature refining: a low-temperature refining furnace is used for homogenization by blowing
argon into a
ladle bath, for deoxidation, desulfurization, and removal of inclusions from the steel melt obtained in S1; S3, vacuum degassing: a vacuum degassing furnace is used for gas removal;S4,
Continuous casting: the
molten steel treated in S3 is continuously cast to form a
continuous casting billet, this process comprising three sub-steps: S41, a
ladle is transferred to a
continuous casting machine for
casting and the
molten steel passes through a
ladle nozzle into a
tundish; S42, after a level of
molten steel has risen to a starting position for
casting,
continuous casting begins, with the molten steel flowing into a mold, employing a three-stage
crystallization process during
crystallization: in an initial stage, i.e., in the first 15 minutes of the total
casting time, the mold uses a non-
sinusoidal vibration, this vibration process occurring with an amplitude of ±4.5 to 5 mm, a vibration frequency of 120 to 130 min-1 and a correction rate a of 19.6% to 20.3%;In an
intermediate stage, i.e., from the completion of the initial stage until 30 minutes before the end of casting, the mold uses a
sinusoidal oscillation together with
electromagnetic stirring, this oscillation process occurring with an amplitude of ±4 to 4.5 mm, an oscillation frequency of 130 to 140 min-1 and an
electromagnetic stirring current of 260 to 270 A; in a
late stage, i.e., from the completion of the
intermediate stage until the end of casting, the mold uses a non-
sinusoidal oscillation, the oscillation process occurring with an amplitude of ±3 to 3.5 mm, an oscillation frequency of 140 to 150 min-1 and a correction rate a of 22.1% to 23.6%; S43, the billet is pulled from the mold and then proceeds to the next process;S5, Aging by
slow cooling: a continuously cast round billet is rapidly placed in a
slow cooling pit at a temperature of 900 to 950 °C, using a progressive
slow cooling approach from very slow cooling to medium slow cooling to weak slow cooling, where the very slow cooling lasts 8 to 9 hours, uses a sealed slow cooling lid and is carried out at a
cooling rate of 5 to 8 °C / h, where the medium slow cooling lasts 5 to 7 hours, uses a semi-sealed slow cooling lid and is carried out at a
cooling rate of 20 to 30 °C / h, where the weak slow cooling lasts 10 to 20 hours, uses an open slow cooling lid and is carried out at a
cooling rate of 50 to 80 °C / h, subsequently yielding a continuously cast steel billet for
wind power;wherein in the continuously cast steel billet for
wind power, an ACN phase in the range of 0.1 to 5.5 micrometers is formed at a
grain boundary, where A in the ACN phase refers to Nb, V, and Ti; wherein within the
grain boundary, a
copper-rich nanophase in the range of 0.3 to 3.8 nanometers is dispersed and distributed; wherein the constituents of the continuously cast billet in
mass percent are as follows: C: 0.085% to 0.096%; Si: 0.18% to 0.20%; Mn: 0.8% to 1.0%; Cr: 0.28% to 0.32%; V: 0.49% to 0.52%; Nb: 0.036% to 0.052%; Mo: 0.38% to 0.42%; Al: 0.025% to 0.035%; Ti: 0.059% to 0.087%; Ni: 0.93% to 0.97%; Cu: 0.11% to 0.17%; N: 0.015% to 0.018%; P: ≤0.007%; S: ≤0.004%; O: ≤20 ppm and the remainder is Fe.