公开(公告)号：EP2743364A4

公开(公告)日：2015-11-04

申请号：EP12822363

申请日：2012-08-08

申请人： NIPPON STEEL & SUMITOMO METAL CORP

发明人： MARUYAMA NAOKI ,  YOSHINAGA NAOKI ,  AZUMA MASAFUMI ,  SAKUMA YASUHARU ,  ITAMI ATSUSHI

IPC分类号： C22C38/00 ,  B21B3/00 ,  C21D9/46 ,  C22C38/14 ,  C22C38/58 ,  C23C2/02 ,  C23C2/28

CPC分类号： C22C38/50 ,  C21D8/0263 ,  C21D8/0426 ,  C21D8/0473 ,  C21D8/0484 ,  C21D9/56 ,  C21D2211/002 ,  C21D2211/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/42 ,  C22C38/48 ,  C23C2/02 ,  Y10T428/12972

摘要： Hot rolled steel sheet which has a maximum tensile strength of 600 MPa or more and has an excellent low temperature impact energy absorption and HAZ softening resistance and a method of production of the same are provided, that is, sheet which contains, by mass%, C: 0.04 to 0.09%, Si: 0.4% or less, Mn: 1.2 to 2.0%, P: 0.1% or less, S: 0.02% or less, Al: 1.0% or less, Nb: 0.02 to 0.09%, Ti: 0.02 to 0.07%, and N: 0.005% or less, where 2.0‰¤Mn+8[%Ti]+12[%Nb]‰¤2.6, has a balance of Fe and unavoidable impurities, has an area percentage of pearlite of 5% or less, has a total area percentage of martensite and retained austenite of 0.5% or less, has a balance of a metal structure of ferrite and/or bainite, has an average grain size of ferrite and bainite of 10 µm or less, has an average particle size of alloy carbonitrides with incoherent interfaces which contain Ti and Nb of 20 nm or less, and has a yield ratio of 0.85 or more.

公开(公告)号：EP2902520A4

公开(公告)日：2016-03-16

申请号：EP13841281

申请日：2013-09-26

申请人： NIPPON STEEL & SUMITOMO METAL CORP

发明人： MARUYAMA NAOKI ,  YOKOI TATSUO ,  TANAHASHI HIROYUKI ,  SETO ATSUSHI ,  ITAMI ATSUSHI

IPC分类号： C22C38/00 ,  C21D9/46 ,  C22C38/58

CPC分类号： C23C30/005 ,  B32B15/01 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0221 ,  C21D8/0263 ,  C21D8/0278 ,  C21D8/0426 ,  C21D8/0463 ,  C21D9/46 ,  C21D2211/001 ,  C21D2211/004 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  Y10T428/12972

摘要： A hot rolled steel sheet consisting of, in mass%, C: 0.05% to 0.15%, Si: 0% to 0.2%, Al: 0.5% to 3.0%, Mn: 1.2% to 2.5%, P: 0.1% or less, S: 0.01% or less, N: 0.007% or less, Ti: 0.03% to 0.10%, Nb: 0.008% to 0.06%, V: 0% to 0.12%, one or more of Cr, Cu, Ni, and Mo: 0% to 2.0% in total, B: 0% to 0.005%, one or more of Ca, Mg, La, and Ce: 0% to 0.01% in total, total amount of Si and Al: 0.8 × (Mn-1)% or more, total amount of Ti and Nb: 0.04% to 0.14%, and the balance: Fe and impurities. In a structure of steel, a total area ratio of martensite and retained austenite is 3% to 20%, an area ratio of ferrite is 50% to 96%, and an area ratio of pearlite is 3% or less. In a superficial layer part, the thickness in a sheet thickness direction of a region in which a network-like oxide is present is less than 0.5 µm, and a maximum tensile strength is 720 MPa or more.

摘要翻译： 以质量％计含有C：0.05〜0.15％，Si：0〜0.2％，Al：0.5〜3.0％，Mn：1.2〜2.5％，P：0.1％以下的热轧钢板 ，S：0.01％以下，N：0.007％以下，Ti：0.03％〜0.10％，Nb：0.008％〜0.06％，V：0％〜0.12％，Cr，Cu，Ni， Mo：总计为0〜2.0％，B：0〜0.005％，Ca，Mg，La，Ce中的一种以上，总计为0〜0.01％，Si与Al的总量为0.8×（Mn -1）％以上，Ti和Nb的总量为0.04〜0.14％，余量为Fe和杂质。 在钢的结构中，马氏体和残留奥氏体的总面积比为3〜20％，铁素体的面积率为50〜96％，珠光体的面积率为3％以下。 在表面层部分中，存在网状氧化物的区域的板厚度方向的厚度小于0.5μm，最大拉伸强度为720MPa以上。