Additive manufacturing processes have been investigated for some years, and are commonly used industrially in the field of plastics for small- and medium-sized series. The use of metallic deposition material has been intensively studied on the laboratory scale, but the numerical prediction is not yet state of the art. This paper examines numerical approaches for predicting temperature fields, distortions, and mechanical properties using the Finite Element (FE) software MSC Marc. For process mapping, the filler materials G4Si1 (1.5130) for steel, and AZ31 for magnesium, were first characterized in terms of thermo-physical and thermo-mechanical properties with process-relevant cast microstructure. These material parameters are necessary for a detailed thermo-mechanical coupled Finite Element Method (FEM). The focus of the investigations was on the numerical analysis of the influence of the wire feed (2.5–5.0 m/min) and the weld path orientation (unidirectional or continuous) on the temperature evolution for multi-layered walls of miscellaneous materials. For the calibration of the numerical model, the real welding experiments were carried out using the gas-metal arc-welding process—cold metal transfer (CMT) technology. A uniform wall geometry can be produced with a continuous welding path, because a more homogeneous temperature distribution results.

The influence of the cooling time t 8/5 has been examined as part of the ongoing AiF-FOSTA P1020 research project for the development of a new design approach for welded joints on highstrength steels. Four thermomechanically rolled and quenched steel grades were investigated. The temperature-time course of a MAG welding process was thermo-physically simulated in a quenching and deformation dilatometer to evaluate the material behaviour. Subsequently, the influence of the cooling time on the mechanical properties of welds was examined using a flat tensile test specimen with a centric hole. The results of the examinations form the scientific basis for a significant improvement of the current execution rules for welded joints between high-strength steels taking into account mismatching of base material and filler metal.

Im AiF‐FOSTA‐Forschungsprojekt P1020 [1] wurde ein neues Bemessungsmodell für Schweißverbindungen entwickelt. In diesem Zusammenhang wurde ein Kleinteilversuch an Flachzugproben konzipiert, mit dessen Hilfe verschiedene Einflüsse auf die Festigkeit und das Verformungsvermögen der Nähte untersucht wurden. Hierzu gehören solche aus dem Grund‐ und Schweißzusatzwerkstoff, der Abkühlgeschwindigkeit und der Anzahl der Schweißlagen. Im folgenden Beitrag werden das Bemessungsmodell und dessen Eingangsparameter beschrieben. Nach einer Charakterisierung der untersuchten Stähle und Schweißzusatzwerkstoffe wird der Kleinteilversuch zur Bestimmung der mechanischen Eigenschaften der Schweißnähte erläutert. Im Anschluss folgen Parameterstudien, im Rahmen derer wesentliche Einflussgrößen auf die Eigenschaften von Schweißnähten untersucht werden. Auf Basis statistischer Auswertungen werden Schweißnahtfestigkeiten in Abhängigkeit vom Zusatzwerkstoff und der Abkühlzeit t8/5 angegeben.

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The high heat input during fusion welding leads to transformations of the microstructure in the area subjected to welding, mostly resulting in a heterogene crystalline structure and an overall deterioration of the mechanical properties. To reduce the detrimental effect, posttreatment processes which are typically separated from the actual welding process are state of the art. The present work shows the new methodology, WeldForming, which intends to eliminate subsequent treatment processes. The new in-line process combination harnesses the synergies of a welding and a rolling process to ultimately prevent the typical zone formation of the heat affected zone. Experimental investigations combined with a detailed numerical simulation of the coupled welding and forming process indicate the functional proof of the new methodology. The validation of the numerical model is carried out with the aid of temperature profiles, cross sections, and microstructure analysis as well as flow curves determined by upsetting tests on thermomechanical simulation systems.