Effect of Laser Power on Mechanical and Microstructure Properties of Pulsed Nd:YAG Laser Welded Dissimilar DP600-DP1000 Steel Sheets

Authors : Oğuz TUNÇEL, Hakan AYDIN, Şükriye ÇETİN

Pages : 41-46

Doi:10.26701/ems.632173

View : 19 | Download : 7

Publication Date : 2020-03-20

Article Type : Research Paper

Abstract :In the present study, dissimilar dual-phase insert ignore into journalissuearticles values(DP); steel sheets insert ignore into journalissuearticles values(DP600-DP1000); were double-sided welded with Nd:YAG insert ignore into journalissuearticles values(Neodymium-doped Yttrium Aluminum Garnet insert ignore into journalissuearticles values(Y3Al5O12);); laser device and the effect of laser power on mechanical and microstructural properties of welded sheets was investigated. Laser welds were conducted using SISMA SWA300 Nd:YAG laser welding machine in the flat position with the butt joint. DP600 and DP1000 steels with a 1 mm thickness were selected for the experiments. Laser power was changed from 20% to 75%, and other welding parameters were kept constant. To evaluate the welded samples, tensile, microhardness and optical microscope tests were performed. As a result of the study, in high laser power values, good quality welds were obtained. In microstructural studies, it was observed that three different regions were formed in the weld section; fusion zone insert ignore into journalissuearticles values(FZ);, heat affected zone insert ignore into journalissuearticles values(HAZ); and base material insert ignore into journalissuearticles values(BM);. These three regions were composed of different phase structures; FZ: martensite, bainite and retained austenite, HAZ: martensite, bainite, ferrite, retained austenite and tempered martensite, BM: ferrite and martensite. Also, different hardness values were measured in these different regions, particularly in the FZ highest microhardness values were measured due to effective martensite formation.
Keywords : Pulsed Nd YAG laser welding, DP600 steel, DP1000 steel, Laser power, Mechanical properties, Microstructure