Work Hardening and Bake Hardening in Five Body Components - Volvo's New Standard for High-Strength Sheet Steel

The following investigation was carried out to evaluate work hardening and bake hardening in actual body components. Five pressings were made from mild steel and three different grades of high-strength steel with ultimate tensile strengths ranging from 380 to 470 N/mm². The latter were a batch annealed Rephos steel and two other grades of continuously annealed dual-phase (DP) steel. Tensile test specimens were taken from these components to evaluate the work hardening and bake hardening. The results are contained in the report.

A new Volvo standard for high-strength cold-rolled sheet steel has been introduced. To some extent, the formulation of the standard was based on the results of the investigation of work hardening and bake hardening. The form and application of the standard are described in the report.