Welded structure with excellent resistance to brittle crack propagation

Abstract

The present invention relates to a welded structure wherein steel plates having at least parts of the base metal with a brittle crack arrest toughness Kca of 4000 N / mm<1.5> or more are butt welded together so as to form a welded joint, wherein at least one location of the welded joint is provided with a crack control part comprising an arrester member comprising a steel material with a brittle crack arrest toughness Kca of 6000N / mm<1.5> or more and arrester welded joints (6) formed by the arrest member being butt welded to steel plates (1) and wherein outer edges of the arrester member are formed so as to slant from the weld line of the steel plate welded joint (2) by 15 DEG to 50 DEG with respect to the longitudinal direction of the welded joint.

Description

technical field [0001] The present invention relates to a welded structure excellent in brittle crack propagation resistance which controls and suppresses the propagation of brittle cracks when brittle cracks occur in welded joints. [0002] In particular, even when a brittle crack occurs in a welded joint of a welded structure welded by using a thick steel plate, the propagation of the brittle crack can be controlled and suppressed to improve safety, and the brittle crack propagation resistance is excellent. welded structure. Background technique [0003] In recent years, welded structures represented by welded structures for ships such as large container ships and bulk carriers, architectural structures, and civil engineering steel structures have been required to have high safety against damage such as brittle cracks. In particular, the increase in the size of container ships is very obvious. For example, large container ships of 6,000 TEU or more can be manufactured, an...

AI Technical Summary

Problems solved by technology

However, in the welded structure of Patent Document 1, it is effective when the fracture toughness of the base material is very excellent, but when the fracture toughness of the base material is not sufficient, the brittle cracks transferred to the base material side Longer propagation, as the strength of the structure may be significantly reduced

In addition, there are also problems in that the volume of the refilled welded part becomes larger, the process time is prolonged, and the manufacturing cost is also increased.

However, in the case where the welded structure described in Patent Document 2 is applied to a large building, for example, a brittle crack propagating in the welded joint propagates in the welded joint where the preventing member is welded to the steel plate and enters the preventing member. In the member, it remains as it is to prevent the interior of the member from propagating, and then it may propagate again in the welded joint

On the other hand, when the brittle cracks propagating in the welded joint are shifted to the base metal side by the stop member and the position of the welded joint of the stop member to the steel plate, there is also a concern that there will be the following problem in the same way as above: When the fracture toughness of the material is not sufficient, brittle cracks propagate for a long time, and the strength as a welded structure is significantly reduced

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