The invention belongs to the technical field of
welding of high-strength pipeline steel, and relates to a
welding process for longitudinal weld joints of submerged-
arc welding for high-strength pipeline steel. Chemical components of high-strength pipeline steel comprise 0.04%-0.06% of C, 0.08%-0.10% of Si, 1.2%-2.0% of Mn, 0.09%-0.10% of Nb+V+Ti+Zr, 0.2%-0.4% of Mo, 0.8%-1.2% of Ni+Cr+Cu, P equal to or less than 0.004%, S equal to or less than 0.001% and the balance being Fe. Steel comprises carbon equivalent Ceq equal to or less than 0.53% and Pcm equal to or less than 0.22%. Chemical components of
welding wires comprise 0.08% of C, 1.75% of Mn, 0.80% of Si, 0.003% of S, 0.010% of P, 0.138% of Cu, 0.41% of Cr, 0.53% of Mo, 2.22% of Ni, 0.011% of Al, 0.05% of Ti, 0.015% of V, 0,01% of Zr, and the balance being Fe. An X-shaped groove is utilized for the submerged-
arc welding, the angle of the groove is 90 degrees, the truncated edge is 4.8mm, the heat input in welding is 21kj / cm, the welding current ranges from 450-800A, the
arc voltage ranges from 32V to 38V, and the welding speed is 170cm / min. Preheating before welding, heat treatment after welding, interlayer
temperature control are all eliminated, weld joints have excellent comprehensive performances, and various areas of the weld joints have fine
impact ductility reserve and safety allowance.