In some laser welding cases, the low heat input results in a weld which has a high hardness compared to the base material. This can create problems in some cases, where higher fatigue life for the weld is required. One method to improve this problem is to increase the heat input by using hybrid laser arc welding (HLAW). This type of process has several advantages over conventional laser beam welding, including a better gap bridging ability and the possibility to use filler metal to modify weld metallurgy. There are also some disadvantages with HLAW, and the one most prominent is the vast amount of different process parameters. The arc parameters can have a significant effect to the heat input in HLAW. By altering the heat input, the toughness properties of the weld can be improved significantly by decreasing the maximum hardness of the weld. This paper describes, what can be accomplished with HLAW when using moderately high laser power in welding of medium thickness (8-10 mm) structural steel. The paper concentrates especially on the effect of arc parameters.
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