Ferrite-Bainite (FB) steels are a somewhat neglected part of the first generation of Advanced High Strength Steels (AHSS). The combination of ferrite and bainite in the microstructure provides improved stretch flangeability of sheared edges when compared to steels such as Dual-Phase and High Strength Low Alloy (HSLA) steels, other viable candidates for the same applications. Therefore, FB steels are more suitable for parts with complex edges requirements. Furthermore, the production of this steels only uses hot rolling, with no need of cold work or further heat treatments, which makes them cheaper than other options. During an effort to produce a new industrial FB590, the effects of niobium and molybdenum addition in the microstructure distribution were investigated. Electron Backscatter Diffraction (EBSD) was used for the microstructural characterization. The influence of the microstructure on the mechanical properties of the steels was investigated by tensile testing.