29sep12:0013:00Forging materials12:00 - 13:00(GMT+02:00) View in my time Chair: Lander Galdos - Mondragon Unibertsitatea
- 29. september 2022
12:00 Lightweight efforts on heavy duty forging applications 12:00 - 12:30Gürbüz Güzey - Parsan
Lightweight design has been a major topic in the mobility sector for a long time. This applies to forged components, too, which can be found in the powertrain, in the chassis and in other highly loaded application areas. However, heavy duty applications seem to have had a lower motivation in the past to implement lightweight solutions than the passenger car sector. This might be changing in future, due to two reasons. On the one hand, the aim for lower fuel consumption (which might by hydrogen or electric energy, too) demands a lower vehicle weight, which is especially important for high mileage applications like truck. On the other hand, there is a demand for lowering CO₂-emissions during production. If a lighter component can fulfil the demands of the application, minimized material input, which leads to CO₂-savings, may be achieved, depending on manufacturing technology.
Hollow shafts are a good example for efficient lightweight design. Deformation and stresses due to torque and bending increase only minimally when the shaft becomes hollow. Depending on available assembly space, a slight increase of the outer diameter can compensate for the hollow center. These relationships can be shown with some elementary calculations.
For hollow shafts but also for other components like I-beams for truck axles, improved steels with higher yield and tensile strength can be used to increase the fatigue limit. When using higher strength steels, it becomes increasingly important to closely control the inclusion status of the steel as well as the surface quality of the component. For higher demands in component fatigue or lightweight needs, processes to increase the compressive residual stresses on the surface can be used. This can be shot blasting (usually applied for cleaning, but already very useful to induce compressive stresses), shot peening or even heat treatment operations like induction hardening or nitriding.
When developing lightweight components, the design of the part and the choice of manufacturing processes must be strongly interlinked. Leading forging companies are able to execute the component engineering including the validation in-house or with partners, so that an optimum solution can be found with minimum communication interfaces.
12:30 High Mn-Al steel for production of forged components featured by high strength and ductility12:30 - 13:00Giacomo Villa– Politecnico di Milano
High Mn-Al steels are a significant opportunity for the production of high resistant components in the light-weight perspective. Actually, the Al addition decreases the density of steel but if compared to other high strength steels these new grades point out also a high toughness and ductility at room temperature increasing the safety for the users. The combination of mechanical properties of this steel grades makes them resemble the properties of more expensive alloys i.e. Titanium alloys. The final microstructure is dual phase (ferrite-austenite) and is influenced significantly by plastic deformation and by the imposed thermal cycle that rule the precipitation of strengthening carbides and intermetallic phases. A large possibility to modulate the properties exists in order to fit the requirements of designers and users.