COLD FORGED STEEL FOR GEARS AND METHOD OF ITS PRODUCTION Russian patent published in 2024 - IPC C22C38/02 C22C38/04 C22C38/06 C22C38/18 C21D8/00 C21D9/32 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of steel for cold forged gears. Method includes melting and casting steel, which in addition to Fe and unavoidable impurities contains the following chemical elements in wt.%: 0.15–0.17 C, 0.10–0.20 Si, 1.0–1.10 Mn, 0.80–0.90 Cr and 0.02–0.04 Al. Steel is heated and forged or rolled, and then spheroidizing annealing is carried out by heating and holding at 750–770 °C, then cooling at a cooling rate of 5–15 °C/h to 700–720 °C and holding at said temperature, cooling at a cooling rate of 3–12 °C/h up to 660–680 °C and holding, cooling at a cooling rate of 5–20 °C/h to 500 °C or lower, and then unloading and cooling.

EFFECT: steel has hardenability meeting the following requirements: J1.5: 38–42 HRC, J3: 35–39 HRC, J5: 30–34 HRC, J7: 26–30 HRC, and J9: 21–25 HRC, wherein said hardenability each has range of 4 HRC or less.

10 cl, 2 dwg, 4 tbl