Speaker
Description
The increasing demands on part complexity and tailored properties in form of local strength and ductility cannot be met with a conventionally manufactured hot-stamped body part. In order to meet the requirements of safety-relevant body parts, partial hot stamping is increasingly used in the industry. One approach to achieve tailored properties on hot-stamped parts is based on controlled cooling of the blank prior to forming and quenching. The related furnace technology is based on a special chamber in which a cooled aluminum mask protects local areas of the blank from thermal radiation and at the same time absorbs the blank's own radiation. The use of different sheet thicknesses and materials can influence the controlled radiation exchange and can lead to lower process limits. In order to analyse these process limits, blanks made of the materials 22MnB5 AS150 and 8MnB7 AS150 are partially pre-cooled in different sheet thicknesses and then hot-stamped. In addition, the process is simulated with AutoFormR10® and validated by the experimental results obtained. The results show that the sheet thickness is a key influencing factor in the process and significantly affects the mechanical properties after partial hot stamping. Especially with sheet thicknesses ≥ 2 mm, the effectiveness of the radiation exchange for controlled pre-cooling and phase transformation is limited.