METHOD FOR PRODUCTION OF COLD-ROLLED ANNEALED ROLLED PRODUCTS FROM IF-STEEL Russian patent published in 2020 - IPC C21D8/04 C22C38/14 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to a method for production of cold-rolled stock from ultra low-carbon IF-steels (Interstitial Free – steel without interstitial atoms), which can be used in automotive industry. Performing steel melting, casting, hot rolling, etching, coiling of strips in rolls, cold rolling, recrystallization annealing in bell furnace and tempering, at that steel of unified chemical composition is produced, containing, wt%: C – 0.002–0.006; Si – 0.005–0.020; Mn – 0.08–0.13; Al – 0.03–0.06; Ti – 0.03–0.08, Fe and unavoidable impurities – balance, temperature of hot rolling end in roughing group of stands of continuous broadband mill is assigned in accordance with relationship T_err≤830 [Ti]+1025, where T_err is the end temperature of rolling, °C, [Ti] is titanium content, wt%, 830 and 1025 are empirical coefficients, coiling temperature of hot-rolled strips is assigned in accordance with relationship T_cl=[15δ_R+50]±15 °C, where T_cl is the coiling temperature, °C, δ_R is the required minimum value of the relative elongation, %, 15 and 50 are empirical coefficients, and temperature of recrystallisation annealing in cap furnace is assigned in accordance with dependence T_ann=[5δ_R+490]±10 °C, where T_ann – temperature of recrystallization annealing, °C, δ_R – required minimum value of relative elongation, %, 5 and 490 – empirical coefficients.

EFFECT: production of rolled products with level of properties corresponding to steels of grades DC05, DC06 and DC07 to EN 10130, that is creation of cassette technology, while maintaining high plasticity and stamping characteristics.

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