Gas-shielded arc welding method, welded joint, and method for producing welded joint
AssigneeJfe Steel Corporation
InventorsAtsushi Takada, Takahito Ito, Seiji Fujisawa, Atsushi Ishigami
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Abstract
A gas-shielded arc welding method is disclosed and includes joining steel materials together by narrow-gap multilayer welding. A groove between the steel materials has an groove angle θ of 20° or less, and a root gap G (mm) that is a gap at a lower portion of the groove is 7 to 15 mm. Root pass is performed in one pass using a ceramic-made backing material at a welding current I (A) of 250 to 400 A and a welding voltage V (V) of 25 to 45 V while a value [Q/G] obtained by dividing a welding heat input Q (KJ/mm) computed using a prescribed formula by the root gap G (mm) is controlled within a range of 0.32 to 0.70.
Claims20
A gas-shielded arc welding method comprising:
- joining steel materials together by narrow-gap multilayer welding,
- wherein a groove between the steel materials has an groove angle θ of 20° or less, wherein a root gap G (mm) that is a gap at a lower portion of the groove is 7 to 15 mm, and
- wherein root pass is performed in one pass using a ceramic-made backing material at a welding current I (A) of 250 to 400 A and a welding voltage V (V) of 25 to 45 V while a value [Q/G] obtained by dividing a welding heat input Q (kJ/mm) by the root gap G (mm) is set within a range of 0.32 to 0.70,
- where the welding heat input Q is given by Q=I×V/S/1000, where I is the welding current (A);
- V is the welding voltage (V);
- and S is a welding speed (mm/second).
Dependencies are inferred from the claim text.