The soft Cr-containing steel includes, on a % by mass basis, C: from about
0.001% to about 0.020%, Si: more than about 0.10% and less than about
0.50%, Mn: less than about 2.00%, P: less than about 0.060%, S: less than
about 0.008%, Cr: from about 12.0% to about 16.0%, Ni: from about 0.05% to
about 1.00%, N: less than about 0.020%, Nb: from about 10.times.(C+N) to
about 1.00%, Mo: more than about 0.80% and less than about 3.00%, wherein
the contents of alloying elements, represented by Si and Mo, respectively,
on a % by mass, satisfy the formula Si .ltoreq.1.2-0.4 Mo, so as to
prevent precipitation of the Laves phase and to stably secure an effect of
increasing high-temperature strength due to solid solution Mo.
L'acciaio Cr-contenente molle include, su un % dalla base totale, C: da circa 0.001% a circa 0.020%, silicone: più circa 0.10% e meno circa 0.50%, manganese: meno circa 2.00%, P: meno circa 0.060%, S: meno circa 0.008%, Cr: da circa 12.0% a circa 16.0%, Ni: da circa 0.05% a circa 1.00%, N: meno circa 0.020%, N.B.:: da circa 10.times.(C+N) a circa 1.00%, Mo: più circa 0.80% e meno circa 3.00%, in cui il contenuto dei leganti, rappresentato entro Si ed il Mo, rispettivamente, su un % da massa, soddisfano il ltoreq.1.2-0.4 Mo del silicone di formula, in modo da impedire la precipitazione della fase di Laves ed assicurare stabile un effetto di aumento della resistenza a temperatura elevata dovuto la soluzione solida Mo.
