This invention relates to a stainless steel gasket having markedly improved
strength and fatigue properties due to precipitation strengthening. Its composition
comprises C: at most 0.03%, Si: at most 1.0%, Mn: at most 2%, Cr: 16.0%-18.0%,
Ni: 6.0%-8.0%, N: at most 0.25%, if necessary Nb: at most 0.30%, and a remainder
of Fe and unavoidable impurities. After cold rolling, final annealing is carried
out, and after a structure is formed of recrystallized grains with an average grain
diameter of at most 5 m having an area ratio of 50-100% and an unrecrystallized
portion having an area ratio of 0-50%, a metal gasket is formed by steps including
temper rolling with a reduction of at least 30% to make the area ratio of a strain
induced martensite phase at least 40%, and forming and heat treatment at 200-350
C. The metal gasket has a duplex phase structure of at least 40% martensite in
which chromium nitride is precipitated and a remainder of austenite, or it has
a single phase structure of martensite in which chromium nitride is precipitated,
and it has Hv of at least 500.
