Hot-rolled ferritic stainless steel sheet having excellent formability and method for manufacturing same
AssigneePosco
InventorsJunghyun Kong, Jinsuk Kim, Nayeon Chu
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Abstract
The present invention pertains to a hot-rolled ferritic stainless steel sheet having excellent formability, which has an R-bar value of at least 1.08 and satisfies TS/YS≤1.5 representing the ratio of tensile strength (TS) to yield strength (YS) after a steel, containing 0.001-0.1% of C, 10.0-14.0% of Cr, 0.001-0.5% of Ti, 0.001-0.5% of Nb, 0.001-1.5% of Ni, 0.001-1.5% of Mn, 0.001-1.0% of Cu, 0.001-2.0% of Si, 0.001-0.1% of N, and 0.1% or less of Al, with the remainder comprising Fe and inevitable impurities, is hot-rolled and then pre-rolled at a reduction ratio of 30% or more.
Claims3
A hot-rolled ferritic stainless steel sheet with excellent formability having a value of R-bar being 1.08 or more and satisfying a ratio of yield strength (YS) and tensile strength (TS), TS/YS≤1.5, after hot rolling a steel comprising, in percent by weight (wt %), 0.001 to 0.1% of C, 10.0 to 14.0% of Cr, 0.001 to 0.5% of Ti, 0.001 to 0.5% of Nb, 0.001 to 1.5% of Ni, 0.001 to 1.5% of Mn, 0.001 to 1.0% of Cu, 0.001 to 2.0% of Si, 0.001 to 0.1% of N, 0.1% or less of Al and the remainder having Fe and unavoidable impurities and pre-rolling the steel at a reduction rate of 30% or more.
A method of manufacturing a hot-rolled ferritic stainless steel sheet with excellent formability, the method comprising:
- manufacturing a slab by continuously casting a steel comprising, in percent by weight (wt %), 0.001 to 0.1% of C, 10.0 to 14.0% of Cr, 0.001 to 0.5% of Ti, 0.001 to 0.5% of Nb, 0.001 to 1.5% of Ni, 0.001 to 1.5% of Mn, 0.001 to 1.0% of Cu, 0.001 to 2.0% of Si, 0.001 to 0.1% of N, 0.1% or less of Al and the remainder having Fe and unavoidable impurities;
- reheating the manufactured slab;
- hot rolling the reheated slab;
- performing pre-rolling at a reduction rate of 30% or more to satisfy a value of R-bar being 1.08 or more and a ratio of yield strength (YS) and tensile strength (TS), TS/YS≤1.5;
- and
- performing hot annealing.
Dependencies are inferred from the claim text.