The invention discloses a 60-120mm improved weather-proof structural steel S355K2W
thick plate and a production method thereof. The weather-proof structural steel S355K2W
thick plate comprises the following chemical components by
mass percent: 0.08-0.15% of C, 0.20-0.45% of Si, 1.20-1.45% of Mn, less than or equal to 0.018% of P, less than or equal to 0.007% of S, 0.015-0.050% of Als, less than or equal to 0.15% of Nb+V+Ti, 0.45-0.70% of Cr, 0.30-0.50% of Cu, and the balance of Fe and residual elements. A technological process of the weather-proof structural steel S355K2W
thick plate comprises the steps of high-quality molten iron and KR molten iron pretreatment, a 100 / 120t top-bottom combined blowing converter, LF (
ladle furnace) refining, vacuum degassing treatment,
casting blank
pile cooling for 24-60h, a pusher type
heating furnace, a 3800m
rolling mill, ACC (accelerated)
laminar cooling, an 11-roll thermal straightener,
pile cooling, finishing, external inspection, fault detection and warehousing. The weather-proof structural steel S355K2W thick plate and the production method have the benefits that the performance of the steel plate can reach a requirement of a
national standard in a TMCP (
thermal mechanical control
processing) rolling and steel plate piling
slow cooling mode under the condition of constant traditional S355K2W carbon equivalent; a production technology is simplified; a heat treatment process is cancelled; the production
energy consumption is reduced; and the production cost is lowered greatly.