Influence of shielding gas composition on weld structure in pulsed Nd: YAG laser welding

Journal of Advanced Materials and Processing

مقاله 6، دوره 1، شماره 3، مهر 2013، صفحه 35-42   

نوع مقاله: Research Paper

نویسندگان

M jokar^{* 1}؛ F MalekGhaini¹؛ M. J. Torkamany²

¹Department of Engineering Materials, TarbiatModares University, Tehran, Iran

²Department of Engineering Materials, TarbiatModares University, Tehran, Iran -Iranian National Centre for Laser Science and Technology (INLC), Tehran, Iran

چکیده

This work studied the effect of additions of carbon dioxide to argon shielding gas on the weld shape and microstructure of ST14 steel in pulsed Nd: YAG laser welding. By additions of carbon dioxide up to 15%,the weld area and depth/width ratio decreases while rising of carbon dioxide up to 25% causes increasing of weld area and depth/width ratio. It is observed that the weld metal microstructure is mainly constructed from polygonal ferrite under 0 to 15% CO₂ additions to argon, but both polygonal and acicular ferrites are observed as the CO₂ level of Ar+ CO2 mixtures increases from 15 to 25%. The shape and microstructure of pulsed Nd: YAG laser welds is believed to be closely related to laser absorption coefficient, laser energy absorption on the work-piece surface and formation of oxide layer on the work-piece surface.

کلیدواژه‌ها

Laser Welding؛ Pulsed Nd: YAG laser؛ Argon shielding gas؛ Carbon dioxide؛ Weld microstructure