Steel is strong, stiff, formable, widely available and cost-effective and it’s for these reasons it continues to be the material of choice for the chassis systems in mainstream passenger cars and light commercial vehicles. Conventional micro-alloyed high-strength steel grades remain the most commonly used in chassis applications because this product family offers designers a cost-effective material featuring the necessary strength combined with excellent durability performance.
However there is increasing pressure on automotive designers to reduce the weight of new cars in order to deliver better performance, including better fuel economy. This focus extends to the chassis, but reducing chassis weight is a difficult task. The system is often positioned within a heavily package-constrained area which means that the designer only has a very limited space in which to design an optimised assembly (see figure ‘Package constraints in chassis’). The design must also meet critical performance requirements related to durability and stiffness. Reducing weight by replacing a panel with a thinner, higher strength material will not necessarily work in the chassis system because stiffness performance will be negatively affected.
Material solutions can help designers achieve lighter chassis designs. Stronger materials increase component durability or safety performance and more ductile materials allow the designer to develop more complexly shaped components which fit smaller package spaces. Tata Steel has developed a suite of advanced high-strength steel grades that meet both needs by combining high strength with improved ductility.
This paper describes a benchmark study to evaluate the optimal use of Tata Steel’s advanced high-strength steel grades to save chassis weight without any compromise to package or performance requirements.