Process for producing a high strength cold-rolled and heat-treated steel strip, sheet, blank or hot formed product having a bimodal microstructure comprising the steps of: - producing and casting a melt into a slab or cast strip having the following composition; 0.05 - 0.50 wt.% C; 0.50 - 8.0 wt.% Mn; 0.05 - 6.0 wt.% Al_tot; 0.0001 - 0.05 wt.% Sb; 0.0005 - 0.005 wt.% of ∑ (Ca + REM); 5 - 100 ppm N; 0 - 2.0 wt.% Si; 0 - 0.01 wt.% S; 0 - 0.1 wt.% P; 0 - 1.0 wt.% Cr; 0 - 2.0 wt.% Ni; 0 - 2.0 wt.% Cu; 0 - 0.5 wt.% Mo; 0 - 0.1 wt.% V; 0 - 50 ppm B; 0 - 0.10 wt.% Ti. remainder iron and inevitable impurities, - reheating the slab or cast strip to a reheating temperature of between 1100 and 1250 °C; - hot-rolling the slab or cast strip to a hot-rolled strip wherein the finishing temperature is 800 to 950 °C; - cooling and coiling the hot-rolled strip between 650 and 450 °C; - pickling the hot-rolled strip; - cold-rolling the pickled hot-rolled strip, preferably with a total cold rolling reduction of between 40 and 80 %; - optionally producing sheet or blanks from the cold-rolled strip; - heat treating the steel strip, sheet or blank by intercritically annealing, preferably at a temperature between 700 and 900 °C, for a duration of between 1 and 300 s. - cooling the annealed steel strip, sheet or blank to an austempering temperature for an austempering treatment between 500 and 300 °C, preferably at most 480 and/or at least 350 °C, at a cooling rate which is higher than the critical rate for formation of pearlite, and maintained for a duration of 10 to 600s and subsequently cooled to ambient temperatures, so as to achieve annealed steel strip, sheet or blank with bimodal grain microstructure consisting of a ferritic matrix phase having a grain size of between 5 and 20 μm and a second phase consisting of one or more of bainite, martensite and retained austenite with a grain size of at most 5 μm, and wherein the final microstructure contains at least 20 vol.% of δ-ferrite. - producing and casting a melt into a slab or cast strip having the following composition; 0.05 - 0.50 wt.% C; 0.50 - 8.0 wt.% Mn; 0.05 - 6.0 wt.% Al_tot; 0.0001 - 0.05 wt.% Sb; 0.0005 - 0.005 wt.% of ∑ (Ca + REM); 5 - 100 ppm N; 0 - 2.0 wt.% Si; 0 - 0.01 wt.% S; 0 - 0.1 wt.% P; 0 - 1.0 wt.% Cr; 0 - 2.0 wt.% Ni; 0 - 2.0 wt.% Cu; 0 - 0.5 wt.% Mo; 0 - 0.1 wt.% V; 0 - 50 ppm B; 0 - 0.10 wt.% Ti. remainder iron and inevitable impurities, 0.05 - 0.50 wt.% C; 0.50 - 8.0 wt.% Mn; 0.05 - 6.0 wt.% Al_tot; 0.0001 - 0.05 wt.% Sb; 0.0005 - 0.005 wt.% of ∑ (Ca + REM); 5 - 100 ppm N; 0 - 2.0 wt.% Si; 0 - 0.01 wt.% S; 0 - 0.1 wt.% P; 0 - 1.0 wt.% Cr; 0 - 2.0 wt.% Ni; 0 - 2.0 wt.% Cu; 0 - 0.5 wt.% Mo; 0 - 0.1 wt.% V; 0 - 50 ppm B; 0 - 0.10 wt.% Ti. remainder iron and inevitable impurities, - reheating the slab or cast strip to a reheating temperature of between 1100 and 1250 °C; - hot-rolling the slab or cast strip to a hot-rolled strip wherein the finishing temperature is 800 to 950 °C; - cooling and coiling the hot-rolled strip between 650 and 450 °C; - pickling the hot-rolled strip; - cold-rolling the pickled hot-rolled strip, preferably with a total cold rolling reduction of between 40 and 80 %; - optionally producing sheet or blanks from the cold-rolled strip; - heat treating the steel strip, sheet or blank by intercritically annealing, preferably at a temperature between 700 and 900 °C, for a duration of between 1 and 300 s. - cooling the annealed steel strip, sheet or blank to an austempering temperature for an austempering treatment between 500 and 300 °C, preferably at most 480 and/or at least 350 °C, at a cooling rate which is higher than the critical rate for formation of pearlite, and maintained for a duration of 10 to 600s and subsequently cooled to ambient temperatures,