Effects of process parameters on the bead geometry of laser beam butt welded stainless steel sheets.pdf

Int J Adv Manuf Technol DOI 10.1007/s00170-006-0432-7 ORIGINAL ARTICLE K. Manonmani . N. Murugan . G. Buvanasekaran Effects of process parameters on the bead geometry of laser beam butt welded stainless steel sheets Received: 26 April 2005 / Accepted: 3 December 2005 / Published online: 19 April 2006 # Springer-Verlag London Limited 2006 Abstract Laser beam welding (LBW) is a field of growing importance in industry with respect to traditional welding methodologies due to lower dimension and shape distor- tion of components and greater processing velocity. Because of its high weld strength to weld size ratio, reliability and minimal heat affected zone, laser welding has become important for varied industrial applications. With increased use of laser welding in continuous mode, there will be increased dependence on the use of equations to predict the dimensions of the weld bead. In this paper, the development of mathematical equations using a three factor 5- level factorial technique to predict the geometry of weld bead in butt joint of austenitic stainless steel 304 sheet of 2.5 mm thickness are presented. The models developed have been checked for their significance by using F-test and t-test. The direct and interaction effect of the process variables on bead geometry are presented in graphical form for quick analysis. Keywords Laser beam welding . Central composite design . Regression Analysis . SS 304 1 Introduction Laser beam welding (LBW) is a fusion joining process that uses the energy from a laser beam to melt and subsequently crystallize a metal, resulting in a bond between parts. Lasers generate light energy that can be absorbed into materials and converted to heat energy. Because of high power density of the laser beam, laser welding is char- acterized by very narrow fusion zone, narrow weld width and high penetration [1]. The energy input in laser welding is controlled by the combination of focused spot size, focused position, shielding gas, laser beam pow