Excellent local deformability, formability high-strength hot-rolled steel sheet and manufacturing method thereof having excellent orientation dependence less ductile

摘要

PROBLEM TO BE SOLVED: To provide a hot rolled steel sheet having high ductility with excellent local deformability and less orientation dependence of formability.;SOLUTION: The hot rolled steel sheet contains C: 0.02-0.5%, Si: 0.001-4.0%, Mn: 0.001-4.0%, Al+Si≤4.0% by mass%, wherein, in its texture, an average value of x-ray random intensity ratios in {100}011-{223}110 orientation component groups on a sheet face at a sheet depth of at least 5/8-3/8 from the surface of the steel sheet is less than 4.0, the x-ray random intensity ratio in {332}113 crystal orientation is 5.0 or less, an r(rC) value in a direction perpendicular to the rolling direction is 0.70 or more, an r value at an angle of 30° with respect to the rolling direction (r30) is 1.10 or less, and the texture contains, by the area ratio, 5-30% residual austenite, 20-50% ferrite, 10-60% bainite, and 20% or less each of pearlite and martensite.;COPYRIGHT: (C)2012,JPO&INPIT