2.6 Simulation of Weld Pool and Keyhole in Deep Penetration …
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is slightly farther than that of the laser beam center. In other words, the width of the
weld pool increases slightly after the heat source leaves, and there is a small lag at
the position of its maximum value. This shows that there is a lag time for thermal
action, and the latent heat of crystallization from liquid to solid phase transition is
also an important factor.
Figure 2.21 shows the calculation result of weld pool in XOZ plane at laser welding
speed of 0.03 m/s, laser power of 3000 W. Obviously, the front of the weld pool has
a certain inclination, and the asymmetric structure of the weld pool is very obvious.
Figure 2.22 shows the geometric shape and size of the weld pool in YOZ plane
when laser power is 3000 W and welding speed is 0.03 m/s. It can be seen that
the weld pool is symmetrical in the OZ direction but asymmetric in the thickness
Fig. 2.21 Weld pool shape and size in XOZ plane during deep penetration laser welding
Fig. 2.22 Shape and size of the cross section of weld pool in deep penetration laser welding