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Title: Effect of Pulsed Nd: YAG Laser Powers On 304 Stainless Steel Welding

Abstract

In this study, optimum welding parameters are obtained for 1mm thickness type 304 stainless steel welding using the Lumonics JK760TR pulsed Nd:YAG laser. The influences of laser welding parameters such as pulse duration, focal position, frequency, laser power, welding speed, and shielding gas (N2) pressure on penetration defining welding quality are investigated. Also comparisons of overlap ratios are presented between theory and experiment for pulse duration, frequency and welding speed.

Authors:
; ;  [1]
  1. University of Kocaeli, Laser Technologies Research and Application Center, Kocaeli (Turkey)
Publication Date:
OSTI Identifier:
21057152
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 899; Journal Issue: 1; Conference: 6. international conference of the Balkan Physical Union, Istanbul (Turkey), 22-26 Aug 2006; Other Information: DOI: 10.1063/1.2733161; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPARATIVE EVALUATIONS; LASER RADIATION; LASER WELDING; NEODYMIUM LASERS; NITROGEN; PULSES; STAINLESS STEEL-304; THICKNESS; VELOCITY

Citation Formats

Candan, L., Demir, A., and Akman, E. Effect of Pulsed Nd: YAG Laser Powers On 304 Stainless Steel Welding. United States: N. p., 2007. Web. doi:10.1063/1.2733161.
Candan, L., Demir, A., & Akman, E. Effect of Pulsed Nd: YAG Laser Powers On 304 Stainless Steel Welding. United States. doi:10.1063/1.2733161.
Candan, L., Demir, A., and Akman, E. Mon . "Effect of Pulsed Nd: YAG Laser Powers On 304 Stainless Steel Welding". United States. doi:10.1063/1.2733161.
@article{osti_21057152,
title = {Effect of Pulsed Nd: YAG Laser Powers On 304 Stainless Steel Welding},
author = {Candan, L. and Demir, A. and Akman, E.},
abstractNote = {In this study, optimum welding parameters are obtained for 1mm thickness type 304 stainless steel welding using the Lumonics JK760TR pulsed Nd:YAG laser. The influences of laser welding parameters such as pulse duration, focal position, frequency, laser power, welding speed, and shielding gas (N2) pressure on penetration defining welding quality are investigated. Also comparisons of overlap ratios are presented between theory and experiment for pulse duration, frequency and welding speed.},
doi = {10.1063/1.2733161},
journal = {AIP Conference Proceedings},
number = 1,
volume = 899,
place = {United States},
year = {Mon Apr 23 00:00:00 EDT 2007},
month = {Mon Apr 23 00:00:00 EDT 2007}
}
  • This paper reports theoretical and experimental investigations carried out to determine the effect of process parameters on weld metal microstructures of austenitic stainless steels during pulsed laser welding. Laser welds made on four austenitic stainless steels at different power levels and scanning speeds were considered. A transient heat transfer model that takes into account fluid flow in the weld pool was employed to simulate thermal cycles and cooling rates experienced by the material under various welding conditions. The weld metal thermal cycles and cooling rates are related to features of the solidification structure. For the conditions investigated, the observed fusionmore » zone structure ranged from duplex austenite ({gamma}) + ferrite ({delta}) to fully austenitic or fully ferritic. Unlike welding with a continuous wave laser, pulsed laser welding results in thermal cycling from multiple melting and solidification cycles in the fusion zone, causing significant post-solidification solid-state transformation to occur. There was microstructural evidence of significant recrystallization in the fusion zone structure that can be explained on the basis of the thermal cycles. The present investigation demonstrates the potential of the computational model to provide detailed information regarding the heat transfer conditions experienced during welding.« less
  • This investigation is aimed at achieving a near 50-50 % ferrite-austenite ratio of laser welded super duplex stainless steel, UNS S 32760 (Zeron 100). Bead-on-plate welding has been carried out using a 2 kW Nd-YAG laser with 3 different kinds of wave form, Continuous, Sine and Square wave. The weld metals were examined with respect to the phase volume contents by X-ray diffraction. Laser welding involved a large number of variables, interaction and levels of variables. Taguchi Method was selected and used to reduce the number of experimental conditions and to identify the dominant factors. The optimum combinations of controllablemore » factors were found from each set of wave form. The optimum 40-60% ferrite-austenite ratio were realized on some of the combination parameter groups after using the Parameter Design method.« less
  • No abstract prepared.
  • A computational and experimental study was carried out to quantitatively understand the influence of the heat flow and the fluid flow in the transient development of the weld pool during gas tungsten arc (GTA) and laser beam welding of Type 304 stainless steel. Stationary gas tungsten arc and laser beam welds were made on two heats of Type 304 austenitic stainless steels containing 90 ppm sulfur and 240 ppm sulfur. A transient heat transfer model was utilized to simulate the heat flow and fluid flow in the weld pool. In this paper, the results of the heat flow and fluidmore » flow analysis are presented.« less
  • In part I of the paper, the results of the heat flow and the fluid flow analysis were presented. Here, in Part II of the paper, predictions of the computational model are verified by comparing the numerically predicted and experimentally observed fusion zone size and shape. Stationary gas tungsten arc and laser beam welds were made on Type 304 stainless steel for different times to provide a variety of solidification conditions such as cooling rate and temperature gradient. Calculated temperatures and cooling rates are correlated with the experimentally observed fusion zone structure. In addition, the effect of sulfur on GTAmore » weld penetration was quantitatively evaluated by considering two heats of 304 stainless steel containing 90 and 240 ppm sulfur. Sulfur, as expected, increased the depth/width ratio by altering the surface tension gradient driven flow in the weld pool.« less