The invention discloses a 500MPa-grade supercritical CO2
corrosion-resistant pipeline coil plate and a manufacturing method thereof, and the 500MPa-grade supercritical CO2
corrosion-resistant pipeline coil plate comprises the following chemical components: 0.05 to 0.10 percent of C, 0.6 to 0.9 percent of Si, 1.50 to 1.70 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.002 percent of S, 0.10 to 0.30 percent of Cr, 0.35 to 0.45 percent of Mo, 0.03 to 0.05 percent of Nb, 0.01 to 0.03 percent of Ti, 0.02 to 0.05 percent of Al, 0.20 to 0.30 percent of Co, less than or equal to 0.008 percent of N, 1.2 to 4.3 percent of Mo / Cr, 0.75 to 0.92 percent of Mo + Cr + Co, 2.8 to 3.9 percent of Si / Co and the balance of Fe and inevitable elements. The manufacturing method comprises the steps of
smelting, slab
continuous casting,
continuous casting slab heating, rolling, cooling and coiling. In the transverse direction of the rolled plate, Rt0.5 is larger than or equal to 540 MPa, Rm is larger than or equal to 640 MPa, Rt0.5 / Rm is smaller than or equal to 0.87, A50 mm is larger than or equal to 36%,-40 DEG C
impact energy KV8 is larger than or equal to 220 J, and-20 DEG C
drop weight DWTT is larger than or equal to 95%; in the longitudinal direction, Rt0.5 is larger than or equal to 520 MPa, Rm is larger than or equal to 630 MPa, Rt0.5 / Rm is smaller than or equal to 0.86, and A50mm is larger than or equal to 38%; the average
corrosion rate in a 14.5 MPa supercritical CO2 environment is 1t; and 0.05 mm / a. The low-carbon medium-
manganese molybdenum-
chromium-
cobalt-containing
alloy design is adopted, the low-temperature
toughness of a weld joint is guaranteed, the CO2 corrosion resistance and the
oxidation resistance are improved, and higher safety is achieved in pipeline
engineering.