Thickness steel plate for a welded construction with an excellent strength and toughness in a central region of the thickness and small changes in properties due to their thickness and production method therefor

摘要

In the present documents is a thickness of steel plate for a welded construction is described, the excellent strength and toughness in a central area and small changes in properties by the thickness of shows. The steel plate has, on: 0.05 ˜ 0.10% c, 0.10 ˜ 0.5% si, 1.3 ˜ 1.7% mn, 0.0005 ˜ 0.0025% b; 0.005 ˜ 0.03% ti, 0.010% or less n, 0.005 ˜ 0.03% nb, 0.005 ˜ 0.055% soℓ. Al, the balance being fe and further unavoidable contaminations, expressed as% by weight, wherein a content ratio of ti / n 2.0 or greater, and a by means of a print-out 1 represented cp 40 ˜ 50 is. Cp = 165 ×% c + 6, 8 ×% si + 10.2 x% mn + 80.6 ×% of nb + 9.5 ×% cu + 3.5 ×% ni + 12.5 ×% cr + 14.4 ×% mo .. (1).