120mm low temperature pressure vessel 16MnDR steel thick plate and production method thereof

The invention discloses a 120mm low temperature pressure vessel 16MnDR steel thick plate. The thick plate comprises the following chemical components by weight percent: 0.10-0.17% of C, 0.25-0.45% of Si, 1.10-1.40% of Mn, 0.015% or less of P, 0.005% or less of S, 0.015-0.055% of Als, 0.015-0.045% of Nb, 0.010-0.020% of Ti and the balance Fe and residual elements. The carbon equivalent [Ceq = C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15] is no more than 0.40. The production method comprises the following technologies: KR molten iron pretreatment, converter smelting, argon-blowing treatment, ladle furnace (LF) refining, vapor deposition (VD) refining, die casting, heating, controlled rolling and controlled cooling, stack cooling and heat treatment. On the basis of ensuring the 16MnDR components, the content of harmful elements in the steel such as P and S which can influence the plasticity and toughness of the steel plate can be strictly controlled; the heating cycle of steel rolling is strictly controlled, the finish rolling temperature, re-reddening temperature and the cooling rate are strictly controlled in the rolling process; and by adopting the methods such as steel plate stacking and slow cooling, each performance index of the 120mm steel plate of the 16MnDR steel can meet the standard requirement.