To improve manufacture performance, such as formability and weldability, for our automotive customers as well as structure performance, mainly lightweighting and crashworthiness, of vehicle components, Nucor Corporation has developed hot rolled multi-phase high performance steels using the highly energy-efficient and sustainable Compact Strip Production (CSP®) process.
This presentation briefly describes the challenges met during the course of this product development, including the thermo-mechanical process during hot rolling and cooling strategies at run-out table to control recrystallization kinetics, refine austenite grains and optimize multi-phase microstructure in final coils. Some hot rolled coils were successfully galvanized, demonstrating their excellent coatability. The successful automotive applications are also presented. Compared to the most commercially available hot rolled high strength products produced at integrated steel mills, Nucor CSP®–manufactured multiphase steels exhibit superior stamping performance. Moreover, Nucor products are more sustainable, with approximately one fifth of CO2 emission per ton of steel produced.