Investigation effect on laser welding quality of laser welding parameters

Laser welding process has many advantages the other techniques. Low heat input, narrow HAZ, low stress strain and distortion, high welding speed, high penetration, smouth welding sections, high structural strength and automatic process are primary advantages of the laser welding. Moreover high efficiency and being economical leading less error rates are other advantages. In this work AISI 304, 50x40 mm stainless steel test items with 2,0 mm thickness were but laser welded. These 20x80 mm test items were tested in guidance with metallographic investigation, measuring hardness, three point bending test performed as explained in TS 282 EN 910 standarts. According to the results, full penetration has been determined through the thickness (2 mm) and the solidified weld metal has the form of keyhole. With increase of welding speed, weld width decreases. Ferrite phase has been determinated within austenite phase at subgrain and grain boundary of austenite. When welding speed increases, deplation width between weld metal and base metal decreases. In the HAZ through the base metal, ferrite bands have been determined extending to the horizontal direction. There is a relation between welding parameters (laser power, welding speed) and the ferrite bands. Hardness of the weld metal is getting higher from base metal to deplation zone. As the heat input increase the hardness of the weld metal and the bending strength are generally increase.