Thick steel plate having excellent low-temperature strain aging impact property and manufacturing method therefor

Abstract

The present invention relates to a thick steel plate superior in low-temperature strain aging impact properties and a manufacturing method therefor and, more particularly, to a thick steel plate thatis usable as a material in ship building, marine structures, and the like and which has excellent low-temperature strain aging impact properties and a method for manufacturing the same. An embodimentof the present invention provides a thick steel plate having excellent low-temperature strain aging impact properties, the steel plate comprising, by weight: 0.04-0.1% of C; 0.05-0.4% of Si; 1.0-2.0%of Mn; 0.01% or less of P; 0.003% or less of S; 0.015-0.04% of Al; 0.005-0.02% of Ti; 0.35% or less (0 exclusive) of Cu; 0.05-0.8% of Ni; 0.003-0.03% of Nb; 0.002-0.008% of N; 0.0002-0.0050% of Ca; 0.009% or less of Cr; 0.0009% or less of Mo; and a balance of Fe and other inevitable impurities, with the microstructure thereof including 95% by area or greater of ferrite 10 um or less in average grain size, and a manufacturing method therefor.

Description

technical field [0001] The present disclosure relates to a thick steel plate having excellent low-temperature strain-aging impact properties and a method of manufacturing the same, and more particularly to a thick steel plate having excellent low-temperature strain-aging impact properties that can be used as a material in shipbuilding, marine structures, etc., and manufacturing thereof method. Background technique [0002] Recently, due to the depletion of land or offshore energy resources, mining areas have gradually moved to deep sea areas or cold areas. Consequently, drilling, mining, and storage facilities are becoming increasingly complex due to facility expansion, integration, and the like. Steel materials used therein need to have excellent low-temperature toughness to ensure structural stability, and in particular, need to minimize a decrease in toughness due to strain aging phenomenon or the like due to cold working during the fabrication of the structure. [0003...

AI Technical Summary

Problems solved by technology

[0007] However, as structures etc. continue to become larger and more complex, the amount of cold deformation required for steel materials increases, and the temperature of the use environment decreases to the level of the Arctic Ocean

Therefore, it is difficult to effectively prevent the decrease in toughness due to strain aging of steel by conventional methods

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