| 摘要 |
A welded structure provided with a fillet-welded joint obtained by bringing an end surface of a bonding member into contact with the surface of a bonded member having a plate thickness equal to or greater than 50 mm and bonding the bonding member and the bonded member by fillet welding, the weld leg length and/or the welding width of the fillet-welded joint being equal to or less than 16 mm. The welded structure has, on the plane at which the end surface of the bonding member and the surface of the bonded member are brought into contact with each other, a non-welded section at which the joint cross-section is no less than 95% of the plate thickness tw of the bonding member. The fillet welding conditions are adjusted so that the fillet welding metal is such that the relationship between the fracture appearance transition temperature vTrs(°C) of the fillet welding metal and the plate thickness tf of the bonded member satisfies the expression vTrs<=-1.5tf+90, and/or the relationship between the absorption energy vE-20(J) at a test temperature of -20°C and the plate thickness tf of the bonded member satisfies vE-20 (J)>=5.75 (where 50 <= tf (mm) <= 53), and vE-20(J)>=2.75tf(mm)-140 (where tf (mm)> 53). Moreover, by constituting the bonding member from steel plating having a brittle crack propagation stopping toughness K ca of at least 2500Ｎ/mm3/2 at feed temperature, propagation of brittle cracking generated from the bonded member having a plate thickness equal to or greater than 50 mm and having a butt-welded joint section is arrested at the fillet-welded metal section. |
