FIELD: metallurgy.
SUBSTANCE: steel which contains the following, wt %, is made: C 0.18 - 0.30, Co 5 - 7, Cr 2 - 5, Al 1 - 2, (Mo+W/2) 1 - 4, V residues - 0.3, Nb residues - 0.1, B residues - 50 p/mln, Ni 10.5 - 15 on condition that Ni ≥ 7+3.5Al, Si impurities - 0.4, Mn impurities - 0.4, Ca impurities - 500 p/mln, rare earth elements - impurities - 500 p/mln, Ti impurities - 500 p/mln, N impurities - 100 p/mln, S impurities - 50 p/mln, Cu impurities - 1, P impurities - 200 p/mln, O impurities - 200 p/mln if steel has been obtained by means of powder metallurgy, or O impurities - 50 p/mln if steel has been obtained during the production process from liquid metal in the air or in vacuum, and the rest is iron and impurities Steel forging is performed. Softening annealing is performed at 600-675°C during 4 to 20 hours with further cooling in the air. Steel is heated up to 900 - 1000°C at least during 1 hour with conversion to solid solution and further cooling in oil and in the air is performed quickly enough in order to prevent deposition of intergranular carbides in austenitic matrix. Steel is hardened by ageing at 475 - 600°C, preferably at 490 - 525°C, during 5-20 hours. The required shape is given to the part by final treatment.
EFFECT: steel has higher mechanical strength during heating at maintaining the required fatigue and brittleness characteristics.
22 cl, 2 tbl
