The invention relates to the technical field of
metallurgy, and particularly discloses a non-tempered N80 steel-grade
petroleum casing
pipe and a preparation method thereof. The non-tempered N80 steel-grade
petroleum casing
pipe comprises the following components in percent by weight: 0.28-0.32% of C, 0.25-0.40% of Si, 1.55-1.70% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.008% of S, 0.011-0.020% of Nb, 0.05-0.08% of V, 0.007-0.013% of Ti, 0.010-0.040% of Al, 0.013-0.017% of N, smaller than 0.10% of Cr, smaller than or equal to 0.10% of Ni, smaller than or equal to0.10% of Cu, smaller than or equal to 0.020% of As, smaller than or equal to 0.020% of Sn, smaller than or equal to 0.01% of Pb, smaller than or equal to 0.01% of Sb, smaller than or equal to 0.01% ofBi, smaller than or equal to 0.035% of Sn, As, Pb, Sb and Bi and the balance of Fe. Through component adjustment and technology optimization, design requirements on the tensile strength, the yield strength, the elongation and the
impact energy of the N80 steel-grade
petroleum casing
pipe are met; the non-tempered N80 steel-grade petroleum casing pipe is stable in performance; compared with the
tempering technology, the preparation method provided by the invention has the advantages as follows: the same quality requirements are met, the production process is shortened, energy is saved, the manufacturing cost is low, and the production efficiency is improved.