| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a thick steel plate for a marine structure which has excellent fracture toughness and excellent corrosion resistance under a high-chloride environment by an inexpensive and simple means. <P>SOLUTION: The thick steel plate for a marine structure includes, by mass, 0.02-0.1% C, 0.03-0.5% Si, 0.5-2.0% Mn, 0.002-0.08% Al, 0.001-0.008% N, 0.003-0.05% Nb, 0.003-0.05% Ti, 0.03-0.50% Sn and the balance Fe with impurities. The microstructure of the steel plate is includes ferrite transformed from non-recrystallized austenite and a second hard phase, in which the ferrite particle size is 2-15 μm, and the aspect ratio of the second hard phase is less than 10. The thick steel plate may further contain one or more elements selected from Ni, Cr, Mo, V and Cu. <P>COPYRIGHT: (C)2012,JPO&INPIT |
