Verena Kräusel

Ressourcenschonende Produktion: Neue Wege bestreiten – reProd®-Ansatz

Kurzfassung Eine Vielzahl von Ansätzen fokussiert effizientere Produktionsprozesse, die Vermeidung von Abfall und Ausschuss sowie einen effizienteren Gebrauch/Betrieb der Produkte innerhalb eines Lebenszyklus, also vom Rohstoff bis Gebrauchsende. Alle diese haben die Steigerung der Ressourceneffizienz als Ziel gemein. Demgegenüber zeichnet sich der reProd®-Ansatz durch eine zyklusübergreifende Betrachtung aus. Durch eine Verkürzung des Kreislaufprozesses lässt sich bei metallischen Produkten ein enormes Potenzial bzgl. Reduktion des Energiebedarfes als auch der CO2-Emission erschließen. Ca. 70 bis 90 Prozent des Energiebedarfes als auch der Treibhausgasemission werden für das Schmelzen der Metalle und die ersten Verarbeitungsstufen benötigt. Werden aus gebrauchten Gütern Sekundärhalbzeuge gewonnen und direkt weiter verarbeitet, entfallen die energieintensiven Prozesse. Durch „Non-Destructive Recycling“, „Re-use without Melting“ kann somit ein entscheidender Beitrag zur Energiewende sowie zum Klima- und Umweltschutz geleistet werden.

Experimental analysis of the sheet metal forming behavior of newly developed press hardening steels

The aim of this work was the characterization of the newly developed press hardening sheet alloys 1800 PHS and 2000 PHS developed by SSAB with regard to their hot forming behavior on the basis of the experimental determination of relevant mechanical and technological properties. For this purpose conventional and non-conventional sheet metal testing methods were used. To determine the friction coefficient, the strip drawing test was applied, while the deep drawing cup test was used to determine the maximum draw depth. Finally, a V-bending test was carried out to evaluate the springback behavior of the investigated alloys by varying the blank temperature and quenching media. This work provides a technological guideline for the production of press hardened sheet parts made of these investigated sheet metals.The aim of this work was the characterization of the newly developed press hardening sheet alloys 1800 PHS and 2000 PHS developed by SSAB with regard to their hot forming behavior on the basis of the experimental determination of relevant mechanical and technological properties. For this purpose conventional and non-conventional sheet metal testing methods were used. To determine the friction coefficient, the strip drawing test was applied, while the deep drawing cup test was used to determine the maximum draw depth. Finally, a V-bending test was carried out to evaluate the springback behavior of the investigated alloys by varying the blank temperature and quenching media. This work provides a technological guideline for the production of press hardened sheet parts made of these investigated sheet metals.

Implementing Thermomechanical Properties of 22MnB5 Steel during Hot Single-Point Incremental Forming

The strategy in manufacturing hardened parts used in car bodies is to tailor the mechanical properties. This is done by combining together a high-strength region and a high-toughness region to ensure the crash performance required. Other successive secondary operations such as trimming, joining and welding can be improved as a result of the tailoring process. In this work, the mechanical properties of 22MnB5 alloy sheet material produced by single-point incremental forming have been tailored. For this purpose, the sheets were locally heated by induction during the forming process and subsequently cooled. The sheet temperature was controlled by the CNC milling machine feed rate and induction power. As a result, the produced tailored parts consist of three different regions: ductile, transition and hardened regions. The Vickers hardness values were 583 HV1 and 175 HV1 for the hardened and ductile regions, respectively. The proposed application allows forming and quenching at the same time without transfer and to reduce the process time.

Tailoring of mechanical properties of a side sill part made of martensitic stainless steel by press hardening

The present work deals with a technological study to integrate the 1.4034 martensitic stainless steel sheet alloy in the conventional press hardening process. Based on preliminary work, side sill demonstrators with tailored mechanical properties were manufactured by press hardening under conventional process parameters. The resulting microstructure and mechanical properties of the produced parts were characterized. The tailoring of the mechanical properties consists of the development of two sections with completely different mechanical properties in a single part. To achieve this, a half of the blank was insulated with a refractory during austenitization treatment. This avoided the heating of the insulated side until the austenitization temperature. Therefore, only the non-insulated side was hardened by quenching. Moreover, depending on the austenitization temperature the resulting mechanical properties can be adjusted.

Improvement of Formability in Single Point Incremental Forming of DP 1000 Steel by Induction Heating

This paper provides results from experiments to improve formability of DP 1000 steel in forming a complex profiles in single point incremental forming with induction heating. High attention is rewarded to the straight effect of induction power and tool settings, in order to determine if the heating temperature is sufficient for raising the formability. The steel sheet is formed by a punch in the upper side and synchronized by induction heating for the sheet on the lower side. Investigations show a maximum achievable wall angle of 70°, which was accomplished at 20 kW induction power for the two formed shapes pyramid and cone. The operational efficiency improved by reducing both the forming time and the induction power required obtaining an optimum heating temperature for the sheet blank. The presented method can be used to increase the formability of difficult-to-form metals by using a simple setup.