Patent ID: 8790573

Claim:
A ferritic Cr-contained steel wherein a cold rolled annealed sheet is annealed, after cold rolling, at a final annealing temperature at 1050 to 1200° C., comprising C of about 0.03% or less, Mn of about 5.0% or less, Cr of about 6 to about 40%, N of about 0.03% or less, Si of about 5% or less, and W of about 2.05 to about 6.0% in percent by mass, and Fe and inevitable impurities as the remainder, wherein precipitated W is 0.005% to 0.1% in percent by mass, and an average thermal expansion coefficient between 20° C. and 800° C. is less than about 12.6×10 −6 /° C.