Keyhole depth instability in case of CW CO2 laser beam welding of mild steel

被引:2
作者
Kumar, N. [1 ]
Dash, S. [1 ]
Tyagi, A. K. [1 ]
Raj, Baldev [1 ]
机构
[1] Indira Gandhi Ctr Atom Res, Surface & Nanosci Div, Kalpakkam 603102, Tamil Nadu, India
来源
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES | 2010年 / 35卷 / 05期
关键词
Ambient and under water welding; keyhole collapse; weld depth instabilities; humps; MODEL; OSCILLATIONS;
D O I
10.1007/s12046-010-0040-y
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The study of keyhole (KH) instability in deep penetration laser beam welding (LBW) is essential to understand welding process and appearance of weld seam defects. The main cause of keyhole collapse is the instability in KH dynamics during the LBW process. This is mainly due to the surface tension forces associated with the KH collapse and the stabilizing action of vapour pressure. A deep penetration high power CW CO2 laser was used to generate KH in mild steel (MS) in two different welding conditions i.e. ambient atmospheric welding (AAW) and under water welding (UWW). KH, formed in case of under water welding, was deeper and narrower than keyhole formed in ambient and atmospheric condition. The number and dimensions of irregular humps increased in case of ambient and under water condition due to larger and rapid keyhole collapse also studied. The thermocapillary convection is considered to explain KH instability, which in turn gives rise to irregular humps.
引用
收藏
页码:609 / 618
页数:10
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