WELDED STRUCTURE EXCELLENT IN BRITTLE-CRACKING PROPAGATION STOPPING CHARACTERISTICS

摘要

A welded structure with high brittle crack arrestability suitable for a hull structure is provided. The welded structure includes a fillet weld joint 9 having an unwelded part 4 in a butting face between a web 1 and a flange 2. Preferably, a width n of the unwelded part 4 of the fillet weld joint 9 in the cross section thereof, the ratio X(%) of the width n to the sum L of a plate thickness t of the web 1 and leg lengths 3 (3a and 3b) of fillet weld metal at the left and right, and the brittle crack arresting toughness Kca (N/mm 3/2 ) of the flange at a service temperature satisfy the following expression: X (%) ‰¥ {5900 - Kca (N/mm 3/2 )}/85. More preferably, the width of the unwelded part 4 of the fillet weld joint 9 is in the range of 15% to 90% of the sum L of the plate thickness t of the web 1 and the leg lengths 3 (3a and 3b) of the fillet weld metal at the left and right. If the web 1 has a butt joint 11, the ratio X(%) of the width to the sum L of the plate thickness t of the web 1 at the butt joint 11 thereof and the leg lengths 3 (3a and 3b) of the fillet weld metal at the left and right and the brittle crack arresting toughness Kca (N/mm 3/2 ) of the flange 2 at the service temperature satisfy the above expression.