METHOD OF PREPARATION OF CALIBRATED ROLLED PRODUCT FOR FABRICATION OF HARDWARE FASTENERS Russian patent published in 2015 - IPC C21D8/06 C21D1/20 C21D7/10 

FIELD: metallurgy.

SUBSTANCE: along the whole section and the length of the rolled product the annealing of the calibrated rolled product is performed at 770-790°C within 3-4 hours, cooling with the furnace down to 660-680°C, holding 3-4 hours, cooling with the furnace down to the temperature 140-150°C with holding 1-2 hours, further cooling in air, primary drawing with the shrinkage 17-19%, heating in the furnace with the monitored atmosphere, patentising at 440-460°C, secondary drawing with the shrinkage 4-5%.

EFFECT: high strength and plastic characteristics.

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