Effect of activating flux on laser penetration welding performance of galvanized steel

Abstract

To study the feasvhibility of activating welding technique in increasing the width of low-power pulsed laser penetration weld joint and to improve the efficiency of lowpower laser welding while reducing cost, theoretical analysis and experimental verification are conducted in this study to determine the effects of activating flux Cr 2 O 3 on the welding performance of DC56D galvanized steel plate for a vehicle body. Research data on the variation in weld width, joint microstructure, mechanical properties, distribution of elements, and corrosion resistance are acquired. Results indicate that activating flux can effectively increase the YAG laser energy absorption of the steel plate and melting of parent metals, thus increasing the weld width. Although the joint microstructure is dominated by refined isometric crystals and columnar crystals, the heat-affected zone expands slightly because of the activating flux. No evident diffusion and segregation of active elements are observed in the weld joint. The involvement of activating flux does not change the relative contents and distribution of chemical components of the weld. The welded test piece with activating flux is superior to that without activating flux in terms of tensile strength, microhardness, and corrosion resistance, indicating that the addition of activating flux effectively improves the performance of low-power laser penetration welding test pieces.

Effect of activating fluxes on geometry, hardness, and microstructure of 316L stainless steel in GMAW

“…Applications of activating uxes can improve weld penetration and the mechanical properties of the weld bead. They are effective in joining various compounds such as stainless steel, mild steel, nickel-based alloys, and magnesium-based alloys [1][2][3][4] and can be utilized in various welding processes, including tungsten inert gas (TIG) [2,[5][6][7] , Gas Metal Arc Welding (GMAW) [1] , and laser welding [8,9] . Their application is widespread and commonly used to increase penetration, reduce energy input, enhance mechanical properties, and in uence the microstructure of the weld bead [10] .…”