Ageing strengthening low-temperature container steel with yield strength larger than or equal to 345 Mpa and production method

The invention discloses aging strengthening low-temperature container steel with the yield strength larger than or equal to 345 Mpa. The aging strengthening low-temperature container steel comprises, by weight, 0.04%-0.09% of C, 0.11%-0.22% of Si, 0.6%-1.20% of Mn, smaller than or equal to 0.005% of P, smaller than or equal to 0.003% of S, 0.03%-0.025% of Alt, 0.09%-0.20% of Cu and the balance Fe. The production method comprises molten iron desulphurization; smelting in a converter; performing continuous casting after vacuum treatment; heating the casting blank; performing rough rolling after cooling; finish rolling to the product thickness; coiling after cooling; cutting into sections; carrying out solution treatment; cooling is performed; and aging treatment. According to the invention, the yield strength of the steel plate at room temperature is greater than 345MPa, the tensile strength is 430-640MPa, the ductility is greater than 21%, and the impact toughness of the steel plate at-20 DEG C can reach more