ROUND ROLLED PRODUCTS FROM ALLOYED STEELS MANUFACTURING METHOD FOR THE FASTENERS PRODUCTION BY THE COLD DEFORMATION Russian patent published in 2019 - IPC C21D8/06 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, specifically to the high-quality rolled steel from alloyed steels production method for the fasteners manufacturing by the cold die forging. Performing the workpiece heating to the temperature of 1,080–1,200 °C, hot rolling with the rolling end temperature in the range of 900–1,050 °C and regulated cooling, at that, cooling after rolling is performed with a rate of 0.5–5 °C/s to the T_cool temperature, the subsequent cooling is carried out at a rate of 0.01–0.4 °C/s. up to 400–600 °C, and then the subsequent cooling is carried out at the arbitrary rate, at that, the cooling temperature T_cool is determined depending on the steel composition by the ratio: T_cool=688.8 + 20.4[Si] – 13.5[Mn] + 17.7[Cr] – 13.8[Ni] + 6.5[Mo] ± 10 °C. Rolled products are obtained from the steel containing, wt. %: carbon 0.09–0.47, silicon not more than 0.40, manganese 0.30–0.94, chromium 0.4–1.35, nickel to 0.8, molybdenum 0.15–0.26, sulfur is not more than 0.045, phosphorus is not more than 0.035, copper is not more than 0.30, iron and inevitable impurities are the rest being.

EFFECT: increase in the rolled products mechanical properties.

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