COMPOSITION OF MARTENSITE STAINLESS STEEL, PROCEDURE FOR FABRICATION OF MECHANICAL TOOL OUT OF THIS STEEL AND PART FABRICATED BY THIS PROCEDURE Russian patent published in 2011 - IPC C22C38/52 C22C38/44 C21D8/00 C21D6/00 

FIELD: metallurgy.

SUBSTANCE: there is cast ingot made out of steel containing wt %: 9≤Cr≤13, 1.5≤Mo≤3, 8≤Ni≤14, 1≤Al≤2, 0.5≤Ti≤1,5 at Al+Ti≥2.25, traces of ≤Co≤2, traces of ≤W≤1 at Mo+(W/2)≤3, traces of ≤P≤0.02, traces of ≤S≤0.0050, traces of ≤N≤0.0060, traces of ≤C≤0.025, traces of ≤Cu≤0.5, traces of ≤Mn≤3, traces of ≤Si≤0.25, traces of ≤O≤0.0050, iron and impurities - the rest. The ingot is heat treated and there is produced a semi-finished product heat treated for solid solution at temperature from 850 to 950°C subjected further to fast cryogen treatment at temperature not exceeding - 75°C without an interval below temperature of transformation of Ms and during time sufficient for complete cooling through whole thickness of the part. The part is tempered-aged at temperature from 450 to 600°C and duration of isothermal conditioning from 4 to 32 hours.

EFFECT: steel possesses high corrosion resistance at high mechanical strength.

26 cl, 2 tbl