| 摘要 |
<p num="1"><br/><br/><br/>An extra-low carbon thin steel sheet that through avoiding of inclusion <br/>aggregates in molten steel and through fine dispersing of inclusions in the <br/>steel sheet, realizes secure prevention of surface flaws and cracking at press <br/>molding, and that through promoting of re-growth of crystal grains at <br/>continuous annealing, realizes high r-value (r-value '||to_char('&')||'gt;= 2.0) and elongation <br/>(total elongation '||to_char('&')||'gt;= 50%); and a process for producing the same. There is <br/>provided an extra-low carbon thin steel sheet excelling in surface properties, <br/>moldability and workability, comprising, by mass, 0.0003%'||to_char('&')||'lt;=C'||to_char('&')||'lt;=0.003%, <br/>Si'||to_char('&')||'lt;=0.01%, Mn'||to_char('&')||'lt;=0.1%, P'||to_char('&')||'lt;=0.02%, S'||to_char('&')||'lt;=0.01%, 0.0005%'||to_char('&')||'lt;=N'||to_char('&')||'lt;=0.0025%, 0.01%'||to_char('&')||'lt;=acid-<br/>soluble Ti'||to_char('&')||'lt;=0.07%, acid-soluble Al'||to_char('&')||'lt;=0.003%, 0.002%'||to_char('&')||'lt;=La+Ce+Nd'||to_char('&')||'lt;=0.02% and the <br/>balance of iron and unavoidable impurities, characterized in that at least <br/>cerium oxysulfide, lanthanum oxysulfide and neodymium oxysulfide are contained <br/>in the steel sheet.<br/></p> |
