A weather resistant thick steel plate comprises, by weight, 0.06%-0.9% of C, not more than 0.30% of Si; 1.10%-1.50% of Mn, not more than 0.015% of P, not more than 0.003% of S, 0.035%-0.065% of Als, 0.25%-0.50% of Cu, 0.20%-0.50% of Ni, 0.40%-0.70% of Cr, 0.50%-0.15% of Mo, 0.008%-0.018% of Ti, 0.030%-0.060% of V, 0.015%-0.030% of Nb, not more than 0.0055% of N, 0.001%-0.004% of Ca, 0.0004%-0.0010% of selectively added B, and the balance of Fe and unavoidable impurities. The manufacturing method includes deep desulfurization of molten iron, converter
smelting, LF, RH,
continuous casting, on-line finishing of slabs,
cut-to-length
torch cutting of slabs, heating, TMCP, and
slow cooling of
steel plates. The obtained weather resistant thick steel plate has balanced strong
toughness and strong
plasticity, low
yield ratio,
atmospheric corrosion resistance, excellent
weldability and
fatigue resistance, and is especially applicable to non-
coating high-rise building structures and bridge structures.