Niobium Alloyed High Strength Steels for Automotive Applications

Modern vehicle bodies make intensive use of high strength steel grades to meet the contradicting demand of lighter weight and simultaneously better mechanical performance. For many steel grades microalloying by niobium is the key to achieve their characteristic property profile. In HSLA steels niobium enhances the strength primarily by grain refinement. In interstitial free high strength steels niobium serves as a stabilizing element. Some modern multiphase steels rely on niobium to achieve additional strength via grain refinement and precipitation hardening. Microstructural control constitutes a powerful means to further optimize properties relevant to automotive processing such as cutting and forming. The role of niobium microalloying in that respect will be outlined.