So far, the susceptibility to cracking of AISI 316 has not been modelled under different process conditions, e.g. at different welding speeds or different pulse frequencies. In this paper, the susceptibility to cracking is investigated for a pulsed Nd:YAG laser and a pulsed CO2 laser in a number of systematic laboratory experiments. Both lasers are operated at an average power of 400 W, and in the investigations 5 series of weldings are performed with the CO2 laser and 12 series of weldings are performed with the Nd:YAG laser. In each series the welding speed is varied in order to change the cooling speed and thus the cracking behaviour.
For each welding, the penetration depth, the seam width, the total number of cracks, the accumulated crack length, the accumulated crack length divided by the penetration depth, and, finally, the percentage of primary austenite are measured and compared for the various series. A comparison is made of the Nd:YAG laser welds and the CO2 laser welds.