METHOD OF HOT-ROLLED COILED STOCK FROM ALLOYED HYPOEUTECTOID STEELS THERMAL TREATMENT Russian patent published in 2018 - IPC C21D1/26 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, specifically to the hot-rolled coils of doped hypoeutectoid steels of 50HGFA type heat treatment, intended for the clutch pressure springs manufacturing. To ensure the required mechanical properties and microstructural characteristics of rolled products, stable and uniform in length, rolling is subjected to a three-cycle annealing, at that, the rolled products heating in each cycle is carried out at a rate of 20–60 °C/h to temperature of A_c1+(10–40) °C, held for 10–20 hours, cooled down at a rate of 20–40 °C/h to temperature of A_r1-(10–40) °C, held at a given temperature for a time of τ=(m+5)×K, where m is the roll maximum mass in the bundle, t, K=1.30–2.0 is the empirical coefficient obtained experimentally and is cooled down.

EFFECT: proposed is a method of the hot-rolled coils of alloyed hypoeutectoid steels thermal treatment.

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