Excellent toughness of the weld heat-affected zone, submerged arc welding method of steel

摘要

PROBLEM TO BE SOLVED: To provide a submerged arc welding method for a steel material which is favorably used for the pipe-making welding of a steel pipe of large diameter such as a UOE steel pipe and a spiral steel pipe.;SOLUTION: When performing the submerged arc welding for a steel material from inner and outer sides, the welding condition is set so that the inner surface weld metal sectional area S₁ and the outer surface weld meal sectional area S₂ satisfy inequalities (1), (2), (3). (1) 0.40≤(S₁+S₂)/t²≤0.80; (2) S₁/t²≤0.35; and (3) S₂/t²≤0.45; wherein t denotes the thickness (mm) of the steel material; S₁ denotes the inner surface weld metal sectional area (mm²), except that of a portion overlapping an outer surface weld metal after the welding of the outer side; and S₂ denotes the outer surface weld metal sectional area (mm²).;COPYRIGHT: (C)2011,JPO&INPIT