Grundlegende Untersuchungen zur Gradierung der mechanischen Eigenschaften pressgehärteter Bauteile durch eine örtlich begrenzte Aufkohlung

Description

Hot stamping of ultra-high-strength steel alloys is an established process for the production of safety-relevant body components. Further light-weight potential is offered by components with tailored properties. Previous investigations have focused mainly on process variants to locally improve ductility. Contrary to that, by now, there is no established process variant for achieving a counteracting effect, thus a local increase in strength, while retaining the same component weight. In this context, the carburizing process is promising. Due to the lack of process knowledge, the overall objective of the present dissertation was to develop a basic process understanding for grading the mechanical proper-ties by localized carburization.

For this purpose, process-side and semi-finished product-side influencing factors during carburization were first analyzed. Through a holistic characterization, among other things, a basic process knowledge was developed. Based on this, the extent of the transition zone of graded components and the influence of grading on the mechanical properties were investigated. The findings were verified through a sample component. In addition to transferring the process to another alloy, the potential of carburized semi-finished products for the hot stamping process was also evaluated.