YS 552MPA A GRADE LINEPIPE STEEL PLATE WITH EXCELLENT DEFORMATION CAPACITY AND BRITTLE-FRACTURE ARREST PROPERTY AND THE METHOD FOR MANUFACTURING THE SAME

摘要

Mainly used for construction, offshore structures and line pipes, yield strength 552Mpa thick steel sheet with excellent deformability and brittle fracture stopping characteristics and its manufacturing method are provided.;The thick steel sheet is in weight% C: 0.04-0.1%, Si: 0.05-0.5%, Mn: 1.4-2.0%, Al: 0.01-0.05%, P: 0.02% or less, S: 0.005% or less, Ti: 0.005 -0.02%, N: 0.002-0.01%, Nb: 0.02-0.07%, V: 0.08% or less, Ni: 0.3% or less, Mo: 0.1-0.3%, Ca: 0.0005-0.004%, remaining Fe and other unavoidable impurities It is made up of.;According to the present invention, it is possible to provide a thick steel sheet having a yield strength of 552 MPa, a uniform elongation of 10% or more, and excellent brittle fracture stopping characteristics at cryogenic temperatures.;Line pipe, deformation capacity, brittle fracture stopping property, thick plate, water cooling during rolling, uniform elongation