METHOD OF PRODUCING COLD-ROLLED MILL PRODUCTS Russian patent published in 2021 - IPC C21D1/26 C21D8/04 C21D9/46 C21D9/663 C22C38/52 C22C38/40 C22C38/18 

FIELD: chemistry.

SUBSTANCE: invention relates to production of cold-rolled stock from high-quality carbon steel for production of cartridges. Proposed method comprises steel melting, casting, hot rolling, water cooling, strips coiling, cold rolling, recrystallization annealing and temper rolling. Hot rolling end temperature is maintained in range of 820-890 °C. Strips are coiled at a temperature of not more than 660 °C. Recrystallization annealing is carried out in a cap furnace by heating the stack of rolls at a rate Y = (−2.05÷(−2.01))×M + 110.5, where (−2.05÷(−2.01)) - empirical coefficient from the range, M - maximum weight of the roll in the cage, t, 110.5 - empirical coefficient, during time, h, equal to 1/2 of mass, t, maximum roll in cage to annealing start temperature of 680–720 °C is held to annealing temperature of 650–690 °C for a period of time equal to the heating time is then cooled for 1–4 hours. Melted steel of following composition, wt. %: carbon 0.07–0.22, silicon not more than 0.18, manganese 0.15–0.50, sulphur not more than 0.020, phosphorus not more than 0.030, chromium not more than 0.20, nickel is not more than 0.30, copper is not more than 0.30, aluminium 0.01–0.07, titanium is not more than 0.01, niobium is not more than 0.01, vanadium is not more than 0.01, nitrogen is not more than 0.015, iron and unavoidable impurities is the balance.

EFFECT: higher output of suitable cold-rolled stock due to higher mechanical properties.

1 cl, 2 tbl