Method for evaluating long brittle crack arresting ability in thick steel plate, and testing device and method for manufacturing thick steel plate using same

Abstract

Provided is a testing device and a method for evaluating long brittle crack arresting ability that is appropriate for an actual ship of thick steel plate (mainly thick steel plate having a thickness of at least 50 mm), the thick steel plate having excellent brittle crack arresting ability and being suitable for use in large container ships, bulk carriers, etc. When a tensile load is applied by a tensile tester in the direction perpendicular to the width of a large test sample having a width of at least 1.5 m, and long brittle crack arresting ability is evaluated for a long brittle crack of length 1 m or greater, a transmitting part for transmitting the tensile load from the tensile tester to the large test sample has thickened parts having a thickness at least 2.5 times that of the large test sample on either side of the center in the width of the large test sample spaced apart at least 2.8 times, preferably at least 4.1 times, the width of the large test sample, and the tensile load from the tensile tester is applied in positions on either side of the center of the large test sample in the direction perpendicular to the width by the thickened parts. A testing device having the transmitting part.

Description

technical field [0001] The present invention relates to the evaluation and practice of steel plates (mainly thick steel plates with a plate thickness of 50 mm or more) preferably used for manufacturing mega-container carriers, bulk carriers, etc. A method and test device for the crack propagation arrestability (long brittle crack arrestability) of long brittle cracks. Background technique [0002] Container ships and bulk carriers have structures such as enlarged upper apertures in order to increase carrying capacity, improve cargo handling efficiency, and the like. Therefore, in order to secure the rigidity and longitudinal strength of the hull, it is particularly necessary to thicken the outer plate of the vessel's body in these ships. [0003] In recent years, container ships have become larger, and for large ships of 6,000 to 20,000 TEU (Twenty-foot Equivalent Unit: Twenty-foot Equivalent Unit), the thickness of the hull plating is 50 mm or more. If the plate thickness...

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Problems solved by technology

[0020] In addition, when these steel plates are actually applied to structures, it may be required to verify the performance of long brittle cracks with a length of 1 m or more through a very large test such as a long ESSO test with a width of 1.5 m or more. Test method, details not yet formulated

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