ROTOR MADE OF HIGH STRENGTH STAINLESS STEEL AND METHOD OF ITS MANUFACTURING Russian patent published in 2023 - IPC C22C38/42 C22C38/44 C22C38/46 C22C38/48 G01C19/06 B21J5/02 C21D9/00 

FIELD: metallurgy.

SUBSTANCE: invention is related to manufacturing of a gyroscope rotor from high-strength stainless steel. A rotor blank is prepared from high-strength stainless steel containing the following elements in wt.%: С: 0.03-0.050 Cr: 14.90-15.80, Ni: 5.00-5.70, Cu: 2.20-2.80, (Nb+Ta): 0.35-0.44, Mo: 0.45-0.54, V: 0.06-0.10 Si: 0.20-0.60, Mn: 0.40-0.80, P≤ 0.010, S≤ 0.010, O≤ 0.003, the rest is iron and inevitable impurities. The rotor blank is subjected to the first heating and free forging, and then first annealing and surface treatment to obtain a forged blank. The first heating involves heating the gas oven to a temperature of 750°C, loading the rotor blank into a gas furnace, exposure for 1.5-2 hours, further heating to a temperature of 1140-1170°C at a speed of 200-300°C/h and exposure for 2-3 hours, and the first annealing includes placing the workpiece after free forging in a resistance furnace, heating to a temperature of 640-660°C, exposure for 12-20 hours and cooling to ambient temperature along with the oven. The forged blank is subjected to the second heating, volumetric stamping, and then the second annealing and solid solution treatment to obtain a forging. The second heating involves heating the gas oven to a temperature of 750-780°C, loading the forged billet into a gas furnace, exposure for 1.5-3 hours, further heating to a temperature of 1120-1150°C at a speed of 100-150°C/h and exposure for 1-2 hours. The forging after the second heating is placed into the cavity of the lower die and volume forging is carried out by 5-fold deformation by pressing, and the first deformation is carried out by pressing the forging using the upper stamp under a pressure of 2000-3000 tons, the second and third deformations are carried out by pressing the forging using an upper die under a pressure of at least 5000 tons, the fourth deformation is carried out by pressing the forging under a pressure of 4500 tons, and the fifth deformation is carried out by pressing the forging under a pressure of 4000 tons for 30-40 s. The second annealing involves placing the forging after die forging in a resistance furnace, heating to a temperature of 640-660°C, exposure for 25-30 hours and cooling to the ambient temperature together with the furnace, and solid solution treatment includes placing the forging after the second annealing in a resistance furnace, heating to a temperature of 1035-1045°C, exposure for 1-1.5 hours and cooling in air to a temperature of no more than 32°C. The forging is subjected to rough processing, aging and finishing to obtain a rotor, while aging includes placing the forging after rough processing in a resistance furnace, heating to a temperature of 550-560°C, exposure for 4-4.5 hours and cooling in air to ambient temperature.

EFFECT: production of a rotor with high strength and fatigue resistance is ensured.

6 cl, 6 dwg, 1 tbl, 5 ex