The present invention relates to a steel plate used for a low temperature
pressure vessel and the production method thereof. The steel plate has the main
chemical composition content (wt percent) that C is 0.12-0.19 percent, Si is 0.15-0.45 percent, Mn is 1.2-1.6 percent, Nb is 0.015-0.050 percent, Ti is 0.01-0.03 percent, Ni is 0.10-0.35 percent, Al is 0.015-0.050 percent, and P is 0-0.015 percent; S is 0-0.01 percent, and the residual is Fe and inevitable
impurity. The present invention uses a new process technology of hot billet steel furnace loading, intermediate billet
water cooling, controlled rolling, controlled cooling accelerating, and normalizing, which is easy to be operated, reduces the dosage of the alloying element to the lowest, in particular, largely reduces the use of the
precious metal Ni, the transverse
impact power of the low temperature
toughness 40 below zero is up to 164 J, transverse
impact power of 30 below zero is up to 298 J, and CTOD is
Delta 0.20 equal to 0.40 mm in the test condition that the temperature is 40 below zero. The cost of the steel type is relatively lower, the hourly output is high, the intensity is moderate, the
plasticity is good, the low temperature
toughness is high, the
welding performance is extremely fine, and thereby the steel type can be widely applied to low temperature vessels for storing and delivering low temperature liquid in various industries and the
petroleum and the
chemical industry fields.