Cr containing steel for welded structure

摘要

The present invention provides Cr-containing steel that has satisfactory levels in all of toughness, strength (hardness) and corrosion resistance of HAZ, and that is suitably used as parts for welded structures. Specifically, the present invention provides Cr-containing steel used for a welded structure, the steel being featured or characterized by containing, by mass %, C: not more than 0.020%, Si: not more than 1.00%, Mn: 1.0 to 5.0%, P: not more than 0.050%, S: not more than 0.020%, Cr: 6.0 to 15.0%, Ni: not more than 1.0%, Al: not more than 0.100%, N: not more than 0.020%, and V: 0.03 to 0.30%, the balance consisting of Fe and unavoidable impurities, or further containing Cu: 0.10 to 2.00% or less and Mo: 0.40 to 3.00% or less, wherein an F or F' value calculated by putting values of contents (mass %) of the respective components in the following formula (1) or (2) is not larger than 13.50: 1 $\begin{array}{cc}Fitit\mathrm{value}=\mathrm{Cr}+0.4x\mathrm{Si}+0.2x\mathrm{Al}+5xP-0.4x\mathrm{Mn}-0.7x\mathrm{Ni}-35xC-10xN+10xV& \left(1\right)\\ F^{\text{'}}itit\mathrm{value}=\mathrm{Cr}+0.6x\mathrm{Mo}+0.4x\mathrm{Si}+0.2x\mathrm{Al}+5xP-0.4x\mathrm{Mn}-0.7x\mathrm{Ni}-0.6x\mathrm{Cu}-35xC-10xN+10\end{array}$