HIGH SILICON BEARING DUAL PHASE STEELS WITH IMPROVED DUCTILITY Russian patent published in 2016 - IPC C22C38/04 C22C38/02 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular, to production of dual phase steel used in auto industry. Hot rolled sheet from dual phase steel containing 0.1-0.3 wt% C, 1.5-2.5 wt% Si, 1.75-2.5 wt% Mn, is annealed at temperature from 750 to 875 °C. Obtained annealed sheet is water quenched at temperature from 400 to 420°C and overaged at 400-420 °C to transform martensite contained in the said hot rolled steel sheet in tempered martensite and produce sheet structure containing ferrite and tempered martensite.

EFFECT: sheet has a tensile strength of at least 980 MPa, and a total elongation of at least 15 %.

7 cl, 7 dwg, 4 tbl