HIGH-STRENGTH THICK STEEL PLATE FOR STRUCTURE EXCELLENT IN BRITTLE CRACK PROPAGATION ARREST PROPERTY, AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a high-strength thick steel plate having excellent brittle crack propagation arrest properties and suitably usable for large-sized structures with a plate thickness of ≥50 mm such as vessels, marine structures, low temperature storage tanks, building or civil engineering structures or the like, and to provide a method for producing the same.;SOLUTION: The high-strength thick steel plate has a texture where the intensity in the {100}011 orientation in the rolled face in the central part of the plate thickness is ≥1.7, and also, the intensity in the {100}011 orientation in the rolled face in the 1/4 part of the plate thickness is ≥0.3, in which the aspect ratio in the microstructure in the central part of the plate thickness in the cross-section parallel to the rolling direction is ≤4.0, and has a Charpy fracture transition temperature of ≤-40°C in the 1/4 part of the plate thickness, and preferably has a steel composition containing, by mass, 0.03 to 0.20% C, 0.03 to 0.5% Si, 0.5 to 2.0% Mn, 0.005 to 0.08% Al, and P, S and N by ≤0.0050%, and if required, one or more selected from Ti, Nb, Cu, Ni, Cr, Mo, V, B, Ca and rare earth metals, and the balance Fe with inevitable impurities.;COPYRIGHT: (C)2010,JPO&INPIT