Advanced High Strength Steels (AHSS) for Automotive Applications − Tailored Properties by Smart Microstructural Adjustments

Abstract

The average use of AHSS in car body design has increased significantly over the past 20 years. This growth is not only an average mass growth, but the variety of available grades and property combinations increase, thus supporting fit-for-purpose options for lightweight design. Numerous ideas for future implementation of the so called 2nd and 3rd generation AHSS are proposed. Currently, the concepts mainly focus on the improvement of strength AND ductility as the main drivers for lightweight design. Future concepts have to envision more than these two properties. In particular, formability is presently not well defined as it depends on the applied specific forming process during car manufacturing and, hence, requires different properties, for example, distinguishing local and global formability measures. This extends the known materials concepts to new further dimensions such as uniform elongation, n-value, stretch-flangeability, bending angle, hydrogen embrittlement. A new generation, referred to as "Generation 4.0" follows 3rd generation AHSS which, in turn, opens the manufacturers a new dimension for lightweight design of future vehicles with the use of highly sophisticated materials with exceptional tailored properties, where "tailored" regards to the carefully adjusted overall materials' properties, instead of the spatially varying, as commonly used to describe "tailored blanks".

Development of Lightweight Steels for Automotive Applications

“…Since then, due to the continuous pressure on material development, several new high strength steel grades appeared and reached already the everyday industrial application. Systematic analysis of these developments can be found in several papers from various authors in the literature [3][4][5][6][7]. In the next sections, a systematic classification of these developments will be summarized.…”

Verification of Properties of Joints Made of Advances High Strength Steels in the Conditions of the Complex Thermal Cycles of the HPAW Process

“…The analysis of the development of advanced structural steels implies the tendency of obtaining high strength without compromising the cost efficiency of material plasticity [1]- [3]. It will be possible to shape prefabricated elements of car bodies, cranes and superlight self-supporting structures.…”

Analysis and Multi-objective Optimization on the Stamping of High Strength Steel

“…Much effort was highly paid to the development of high strength steel in the last years. F Ajersch et al [2] reviewed the galvanizing operations of steel to decrease the surface defects and discussed the formability and application of high strength steel in automotive manufacturing area. Some kinds of high strength steel were mentioned and discussed in the study.…”