METHOD FOR PRODUCING COLD-ROLLED PRODUCT FOR AUTOMOTIVE ENGINEERING Russian patent published in 2017 - IPC C21D8/04 C21D9/48 C21D9/663 

FIELD: metallurgy.

SUBSTANCE: method includes steel melting, casting, hot rolling, cooling with water, winding of strips into rolls, cold rolling, recrystallisation annealing in a bell furnace and temper rolling. Melted steel contains, wt %: carbon 0.06-0.12, silicon not less than 0.40, manganese - 1.10-1.50, chromium not less than 0.10, the rest are iron and unavoidable impurities, recrystallisation annealing is carried out to final temperature T=-1.1239×ε+665.42, where 1.1239 is the empirical factor, ε the degree of compression during cold rolling, %, 665.42 is the empirical factor. After that it is kept under a heating bell with switched odd burners for not more than 4 hours, then at a temperature of at least 580°C, the accelerated cooling is carried out under the muffle at 25-35°C/hr rate. In addition, the unpacking of the charge is carried out at temperature not exceeding 90°C, and temper rolling is carried out with reduction of 0.8-1.6%.

EFFECT: increased strength properties while maintaining stamping formability and producing physical-mechanical properties uniform along the length and cross-section of the strip.

3 cl, 3 tbl