Weldability of advanced high strength steels using an Yb:YAG disk laser

In this paper, weldability results of 1030 nm, 6 kW Yb:YAG disk laser welding of various combinations of advanced high strength steels (transformation induced plasticity steel, dual phase steel and boron steel) of 1–2 mm thickness are presented. Weldability is expressed in terms of penetration, weld profile, weld defects, microhardness and melting efficiency. Full penetration keyhole welds with hour-glass shape were produced. Microhardness measurements indicated a substantial increase in hardness in the weld zones, attesting the superiority of laser welding. Analyses revealed that the typical melting efficiency is on the order of 50–70% for full penetration welding. Tensile test results confirmed the high quality of the welds obtained.