HIROSHIMA, Japan—Engineers at Mazda Motor Corp. here have developed the world’s first cold-stamped vehicle body parts made from 1,310-megapascal (MPa) high-strength steel. The parts are used in Mazda’s new-generation Skyactiv vehicle architecture, which will underpin upcoming models starting with the all-new Mazda3 sedan.
High-strength steel enables automakers to make parts from thinner sheet metal while retaining the necessary yield strength. This results in a lighter vehicle body, which contributes to improved handling stability and fuel economy. A strong body is also essential to ensure crash safety performance, and the application of higher-strength steel has been widely anticipated.
Until now, cold-stamping of vehicle body structural members has only been possible with 1,180 MPa or lower-classed steel, due to the material’s formability and the difficulty of ensuring dimensional accuracy after processing.
The Mazda3 uses 1,310 MPa-class high-strength steel for the front pillar inner, the roof rail inner, the hinge pillar reinforcement, the roof rail reinforcement, the No. 2 cross member and the side sill inner reinforcement. That lightweighting effort saves 3 kilograms over the same parts in the previous model.