Thermomechanical laser welding simulation of dissimilar steel-aluminum overlap joints. (15th January 2021)

• Record Type: Journal Article
• Authors: Evdokimov, Anton; Doynov, Nikolay; Ossenbrink, Ralf; Obrosov, Aleksei; Weiß, Sabine; Michailov, Vesselin
• Is Part Of: International journal of mechanical sciences. Volume 190(2021)
• Publication Date: 2021-01-15
• Subjects: Dissimilar steel-aluminum laser welding -- Mechanical properties -- Indentation -- Temperature simulation -- Thermomechanical simulation -- Medium-entropy alloys; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2020.106019
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: Laser-welded austenitic steel 304 - 6082 Al alloy overlap joints are considered. Indentation technique and EDS analysis were used to study St-Al weld metal. The weld metal exhibits nonlinear strengthening with increasing Al concentration. Implementation of weld material model is crucial for prediction of distortions. Abstract: Mixing of steel and aluminum within the weld pool during keyhole laser welding results in a complex dissimilar microstructure, which in turn, initiates a shift in weld metal mechanical properties. In this study, a numerical model for computation of distortions in laser-welded dissimilar overlap joints (austenitic stainless steel 304 – 6082-T6 aluminum alloy), which considers properties of the mixed steel-aluminum weld metal was developed. The required yield strength, Young's modulus, and strain hardening exponent of the weld metal were experimentally determined using the indentation technique coupled with energy-dispersive X-ray spectroscopy. The designed material model calculates the weld elastic-plastic properties as a function of the aluminum concentration. The softening of the alloys in the heat-affected zone was determined by physical simulations and considered as a function of maximum temperature. Computed and measured distortions showed good agreement for various welding regimes with an average deviation of 18.4%. The sensitivity analyses indicated that the application of the developed weld material model significantly improves the accuracy of the thermomechanical simulations. Graphical abstract: Image, graphical abstract