On the Formability of Automotive TRIP Steels
The issue of cost and weight reduction at optimum car crash safety is a driving force behind the growing use of advanced high strength steels, particularly in Europe and Japan. Recent developments in the availability of high strength steel (HSS) sheets in North America; in particular transformation induced plasticity (TRIP) steels, offer an attractive option to the automotive designer for weight reduction and improved safety performance. For example, the use of TRIP steels, as opposed to more conventional steel products such as high strength low alloy (HSLA), in some applications may result in up to 40% part weight reduction at similar vehicle crash performance. When the excellent formability of TRIP steel is considered at product design stage, it may also lead to reducing part count and tooling cost. In this paper the formability of TRIP steels of various gauges is assessed. Experimental forming limit curves (FLCs) are determined for T600 grade.