Abstract
Among the various welding technologies, resistance spot welding (RSW) and laser beam welding (LBW) play a significant role as joining methods for the automobile industry. The application of RSW and LBW for the automotive body alters the microstructure in the welded areas. It is necessary to identify the mechanical properties of the welded material to be able to make a reliable statement about the material behavior and the strength of welded components. This study develops a method by which to determine the mechanical properties for the weldment of RSW and LBW for two dual phase (DP) steels, DP600 and DP1000, which are commonly used for the automotive bodies. The mechanical properties of the resistance spot weldment were obtained by performing tensile tests on the notched tensile specimen to cause an elongation of the notched and welded area in order to investigate its properties. In order to determine the mechanical properties of the laser beam weldment, indentation tests were performed on the welded material to calculate its force-penetration depth-curve. Inverse numerical simulation was used to simulate the indentation tests to determine and verify the parameters of a nonlinear isotropic material model for the weldment of LBW. Furthermore, using this method, the parameters for the material model of RSW were verified. The material parameters and microstructure of the weldment of RSW and LBW are compared and discussed. The results show that the novel method introduced in this work is a valid approach to determine the mechanical properties of welded high-strength steel structures. In addition, it can be seen that LBW and RSW lead to a reduction in ductility and an increase in the amount of yield and tensile strength of both DP600 and DP1000.
Highlights
One major challenge for automotive manufactures is to reduce car body weight and fuel consumption while improving crashworthiness [1,2]
Investigations have shown that in the weld metal of dual phase (DP) steels, a martensitic microstructure is formed when the cooling time t8/5 is less than three seconds [22]
The base metal of DP600 and DP1000 typically shows a mixture of ferrite and martensite microstructures, which was completely converted into a martensite structure after welding
Summary
One major challenge for automotive manufactures is to reduce car body weight and fuel consumption while improving crashworthiness [1,2]. The automotive industry has started to replace traditional low carbon and high-strength low-alloy steel with dual phase steels such as DP600 and DP1000 [3]. DP steels offer exceptional strength and impact resistance combined with good formability that can improve the crash performance of the automobile [4]. RSW and LBW are the most commonly-used joining methods for DP steels in the automotive industry [5]. The characterization of the mechanical properties of the weld metal remains a critical concern to analyze the safety of automotive products [6]. Deal with the fracture behavior of resistance spot-welded steel [7]. Manladan [8] investigated the mechanical properties of resistance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
