The invention discloses high-strength high-
toughness submerged arc welding wires. Chemical components of the wires comprise, by weight, 0.05-0.10% of C, no more than 0.20% of Si, 0.6-1.20% of Mn, 3.00-3.8% of Ni, 0.01-0.05% of Ti, 0.001-0.005% of B, no more than 0.02% of Cu, no more than 0.008% of S, no more than 0.010% of P, no more than 0.005% of As, no more than 0,005% of Sb, no more than 0.005% of Sn, no more than 0.006% of N, no more than 0.05% of O and the balance Fe and unavoidable impurities. A manufacturing method sequentially comprises the steps of molten iron desulphurization, converter iron
smelting, LF furnace refining,
continuous casting, wire rolling, coil rod shelling, acid picking,
borax coating,
wire drawing and
copper plating, and then the finished
welding wires with the diameters being respectively 3.2mm and 4.0mm are manufactured.
Fracture toughness delta0 (-10 DEG C) is more than or equal to 0.25mm, the
welding wires are applicable to 420-460 MPa level low-
alloy high-strength steel, and the
welding wires can be used in welding of the important structures like ocean
engineering structures, bridges, ships and pressure vessels.