FIELD: welding.
SUBSTANCE: invention relates to submerged arc welding of ship steel 5Ni with tensile strength of 630 to 670 MPa. Welding wire is used, the tensile strength of which is from 630 to 710 MPa, wire diameter is 2.4 mm or more, grade INCO-WELD Filler Metal C-276. Welding flux INCOFLUX 9 is used. K-shaped grooving is performed. Welding current is 400–420 A, welding voltage is 31–33 V, welding speed is 25–29 cm/min, weld heat input is 27–33 kJ/cm. Butt joints are continuously welded with equal sheet thickness until the weld is filled. Firing mode is maintained under flux at 350 °C for 1 hour, while maintaining interlayer temperature from 50 to 80 °C. A wire brush is used to clean the weld seam after each welding pass.
EFFECT: method provides high values of tensile strength of the butt weld, impact absorption energy of the seams of the weld, fusion line and heat-affected zone, wherein welded joints have excellent impact strength at low temperatures and characteristics of cold bending.
7 cl, 4 dwg, 3 tbl
