| 摘要 |
<p>The present invention provides a fire resistant steel material excellent in high temperature strength, toughness, and reheating embrittlement resistance containing, by mass%, C: 0.001% to 0.030%, Si: 0.05% to 0.50%, Mn: 0.4% to 2.0%, Nb: 0.03% to 0.50%, Ti: 0.005% to less than 0.040%, N: 0.0001% to less than 0.0050%, and Al: 0.005% to 0.030%, limiting P: 0.03% or less and S: 0.02% or less, satisfying C-Nb/7.74‰¤0.005 and 2‰¤Ti/N‰¤12, and having a balance of Fe and unavoidable impurities and, further, a process for production of a fire resistant material comprising heating a steel slab comprised of this chemical composition to 1100 to 1350°C and hot rolling it by a cumulative reduction rate at 1000°C or less of 30% or more.</p> |
