公开(公告)号：US20230287545A1

公开(公告)日：2023-09-14

申请号：US18144394

申请日：2023-05-08

申请人： POSCO Co., Ltd

发明人： Je-Woong LEE ,  Sang-Ho HAN

IPC分类号： C22C38/04 ,  C22C38/18 ,  C22C38/02 ,  C21D8/02

CPC分类号： C22C38/04 ,  C21D8/0226 ,  C21D8/0236 ,  C22C38/02 ,  C22C38/18 ,  C21D2211/005 ,  C21D2211/009 ,  C22C2204/00

摘要： An aspect of the present invention relates to a high strength steel sheet having an excellent high-temperature elongation characteristic, wherein the sheet comprises, by weight %, 0.4-0.9% of C, 0.01-1.5% of Cr, 0.03% or less (exclusive of 0%) of P, 0.01% or less (exclusive of 0%) of S, 0.01% or less (exclusive of 0%) of N, 0.01% or less (exclusive of 0%) of sol. Al, and a balance of Fe and inevitable impurities, and comprises at least one among 2.1% or less (exclusive of 0%) of Mn and 1.6% or less (exclusive of 0%) of Si; the sheet has a microcrystalline structure including pearlite having an area fraction of 80% or more and ferrite having an area fraction of 20% or less; and the pearlite includes cementite having a major axis length of 200 nm or shorter.

公开(公告)号：US20230092345A1

公开(公告)日：2023-03-23

申请号：US17992245

申请日：2022-11-22

申请人： POSCO Co., Ltd

发明人： Sang-Ho HAN ,  Je-Woong LEE

IPC分类号： C22C38/04 ,  C22C38/18 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

摘要： Provided is a steel sheet by weight percentage (wt %), carbon (C): 0.005 to 0.08%, manganese (Mn): 1.25% or less (excluding 0%), phosphorus (P): 0.03% or less (excluding 0%), sulfur (S): 0.01% or less (excluding 0%), nitrogen (N): 0.01% or less (excluding 0%), soluble aluminum (sol.Al): 0.01 to 0.06%, chromium (Cr): 1.15 to 2.5%, antimony (Sb): 0.1% or less (excluding 0%), at least one selected from the group consisting of nickel (Ni): 0.3% or less (excluding 0%), silicon (Si): 0.3% or less (excluding 0%), molybdenum (Mo): 0.2% or less (excluding 0%), and boron (B): 0.003% or less (excluding 0%), and a remainder of iron (Fe) and other unavoidable impurities, satisfying Expression 1: 1.3≤Mn(wt %)+Cr(wt %)/1.5+Sb(wt %)≤2.7, where Mn, Cr, and Sb refer to contents (wt %) of corresponding elements, respectively; and 1 to 5% of martensite and a remainder of ferrite by an area percentage (area %).