Welded structure

Abstract

The present invention pertains to a welding structure provided with a fillet welded joint obtained by bringing the weld end surface of a joining member into contact with the weld surface of a butt weld joint of a joined member, both members having a plate thickness of at least 50 mm, and joining the joining member and the joined member by fillet welding. The weld leg length and / or the welding width of the fillet welded joint are 16 mm or less. The welding metal in the butt weld joint of the joining member and / or the joined member is set at -65 °C at vTrs-W (°C), and / or a toughness of at least 140 J is set at vE-20-W (J). A non-welded section exists on the surface where the joining member and joined member are brought into contact, where the cross section of the butt weld joint of the fillet welded joint is no less than 95% of the plate thickness (tw) of the joining member. By satisfying a predetermined relationship between vTrs (°C) and / or vE-20 (J) of the fillet welded metal, and the plate thickness (tf) of the joined member, the propagation of brittle cracks is prevented before said cracks lead to large-scale destruction.

Description

Technical field [0001] The present invention, for example, relates to welded steel structures that use thick steel plates for welding construction of large container ships, bulk carriers, etc., and in particular, to the propagation of brittle cracks generated from welded joints before large-scale destruction of the structure is caused. A welded structure with excellent brittle crack propagation stopping performance. Background technique [0002] In order to increase the loading capacity and increase the efficiency of cargo handling capacity, the container ship / bulk carrier has a structure that reduces the partition wall in the cabin and enlarges the opening in the upper part of the ship, unlike oil tankers. Therefore, in container ships and bulk carriers, it is particularly necessary to increase the strength or thickness of the hull shell. [0003] In addition, container ships have become larger in recent years, and large ships such as 6,000 to 20,000 TEU have been built. In addi...

AI Technical Summary

Problems solved by technology

[0007] However, ships built by applying welding equivalent to the welding used in Non-Patent Document 1 to steel plates with a plate thickness of less than 50 mm did not have any problems and had many sailing experience and a steel plate base material with good toughness (shipbuilding Class E steel, etc.) has experience in sufficiently maintaining the ability to stop brittle cracks, and there has been no special requirement for the brittle crack propagation stop characteristics of welded parts of shipbuilding steels in ship classification standards, etc.

However, an increase in the brittle crack propagation stopping toughness Kca leads to an increase in the rolling load during steel plate production, a decrease in productivity, and an increase in production cost.

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