Mazda Debuts Cold-Stamped High-Strength Steel Applications

Mazda Motor Corp. says its latest Skyactiv-Vehicle Architecture is the first production application for cold-stamped advanced high-strength steels rated above 1,200 MPa.

Until now, traditional cold-stamping processes for structural body parts were limited to steels with a tensile strength no higher than 1,180 MPa. This was because of the material’s formability and the difficulty of ensuring dimensional accuracy after processing, Mazda notes.

The carmaker worked with two steel companies—Nippon Steel & Sumitomo Metal Corp. and JFE Steel Corp.—to develop the higher-strength cold-stamping applications. The all-new Skyactiv platform uses third-generation high-strength steels rated at 1,310 MPa.

The first vehicle built on the new architecture is the Mazda3 small car (above). The 2019 model uses 1,310 MPa steel for the front pillar inner, roof rail inner, hinge pillar reinforcement, roof rail reinforcement, No. 2 crossmember and the side sill inner reinforcement. The combined components are nearly 7 lbs lighter than those they replace.

High-strength steel enables the use of parts made from thinner sheet metal while retaining the same yield strength. In addition to reducing weight, Mazda notes that this also can improve driving dynamics.

Carmakers have just begun using third-generation advanced high-strength steels, which combine increased material strengths with improved elongation properties. The first applications started to appear in General Motors, Honda and Nissan vehicles in 2015.