04 October 2011

New high strength steel for Mazda CX-5 bumper beam

Mazda, together with its partner Aisin Takaoka announced their success in developing bumper beam with ultra high strength steel grade 1800MPa. This is in line with Mazda Skyactiv concept that emphasize lightweight material and optimization of load path for its core structure. Usage of 1800MPa grade material for bumper beam yield 4.8kg savings over bumper beam with lower material grade and has 20% better stiffness.

More after the jump.

Usage of high strength material allows thinner cross section to be used to achieve a particular strength. Hence, the resulting structural mass can be reduced. The 1800MPa grade is reputedly the highest strength achieved so far. For today's car, typically, ultra high strength steel with Boron content, stamped via Hot-Press technology can achieved 1500MPa of strength. The application anyway is challenging as it requires the mastery of hot-press technology as well as panel joining method. The materials will tend to be brittle at its yield limit. The technology anyway, is hardly standstill. The 1900MPa is said to be already in the lab and will probably come in stream quicker that we thought.