公开(公告)号：EP2311585A4

公开(公告)日：2016-11-09

申请号：EP09797944

申请日：2009-07-15

申请人： NIPPON STEEL & SUMITOMO METAL CORP

发明人： KIYOSE AKIHITO ,  KAJITANI TOSHIYUKI ,  NIIZUMA MINEO ,  OOTANI YASUHIKO

IPC分类号： B22D11/124 ,  B22D11/00 ,  B22D11/22 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/58

CPC分类号： C22C38/02 ,  B22D11/124 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08

摘要： A continuous cast slab includes the following component: by mass%, C: 0.01 ˆ¼ 0.3%, Si: 0.05 ˆ¼ 0.5%, Mn: 0.4 ˆ¼ 2%, P: 0.03% or less, S: 0.03 or less, Al: 0.005 ˆ¼ 0.03%, Ni: 0.2 ˆ¼ 2%, O: 0.006% or less, and N: 0.006% or less; wherein the balance is composed of Fe and inevitable impurities; wherein a structure in steel in a region within at least 2 mm from a broad surface is composed of ferrite and pearlite and a equivalent circular diameter of ferrite grains in the region is equal to or shorter than 30 µm.