METHOD AND DEVICE FOR CONTINUOUS FORMATION OF BAINITIC STRUCTURE IN CARBON STEEL, MAINLY IN STRIP STEEL Russian patent published in 2012 - IPC C21D1/20 C21D1/607 C21D9/52 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, and namely to manufacturing procedure of hot-dip-galvanised strip of increased strength, which is intended for manufacture of automobile parts by forming. Austenitisation (3) of carbon steel (1) is performed at temperature exceeding austenitisation temperature; then, steel (1) is added to bath (2) containing hardening agent (21) for cooling to the temperature which is lower than austenitisation temperature; steel (1) is brought to temperature of bainitic conversion and exposed during certain period of time at that temperature; at that, the amount of hardening medium (21) and duration of steel contact with hardening medium (21) is such that in general structure of carbon steel (1) placed in bath (2) containing hardening medium (21) there formed is the specified fraction of bainitic structure; at discharge of carbon steel (1) from bath (2) the residues of hardening medium (21) are removed from its surface by gas action; then, carbon steel (1) is moved through isothermic exposure station (13) which is located after bath and in which there performed is conversion of the rest component parts of carbon steel (1) structure to bainite, which is performed at temperature of bainitic conversion and without deflection of carbon steel (1) at its movement till complete formation in it of bainitic structure, and steel (1) is finally cooled at cooling station (17,18).

EFFECT: improving steel strength characteristics with maintenance of high ductility.

33 cl, 1 dwg