For the past decades, the automobile industry has been improving fuel efficiency, passenger safety, and reduction in greenhouse gas emission by adopting advanced high strength steels (AHSS) with both high strength and high ductility. In general, AHSS is classified as the first-generation AHSS (1st-G AHSS), the second-generation AHSS (2nd-G AHSS), and the third-generation AHSS (3rd-G AHSS).

   The 1st-G AHSS, such as dual-phase (DP), complex-phase (CP), and transformation-induced plasticity (TRIP) steels, possesses the high strength of over 600 MPa but the relatively low ductility of below 20%. This low ductility restricts the application of the 1st-G AHSS to automobile parts with complex shapes. The 2nd-G AHSS, such as high Mn TRIP and twinning-induced plasticity (TWIP) steels, shows a remarkable combination of high strength of over 700 MPa and large uniform ductility exceeding 50%. The extraordinary tensile properties of the 2nd-G AHSS result from the high strain hardening rate due to the formation of strain-induced martensite or mechanical twins in the austenite phase during plastic deformation. However, the 2nd-G AHSS has difficulties in mass production, material cost, and welding, which are caused primarily by a lot of alloying elements greater than approximately 17 wt.%. Therefore, nowadays, the 3rd-G AHSS, such as lightweight steel, quenching and partitioning (Q&P) processed steel and medium Mn steel has been attracted because it has a good trade-off between material cost and mechanical properties.

   One of the objectives of LAMP is to investigate the next generation AHSS showing better mechanical properties than 3rd-G AHSS even maintaining reasonable materials cost. This concept is based on optimal using of various strengthening mechanisms simultaneously.