Johan Andersson, Erik Tolf, Anders Jarfors, Anna de Try, Joakim Hedegård

Abstract

In this investigation the performance of the Laser-MIG/MAG process was investigated for the following applications:

• Lap joint welding of AW6063-T6 aluminium alloy.
• Butt joining tubular components in stainless superduplex SandvikSAF 2507.
• Lap joint welding of the coatedhigh strength steels USIBOR1500 P to DOGAL 600 DPZ140.
• Lap joint welding of the stainless steels HyTens 1200and LDX 2101 to the zinccoated C-Mn steel DOGAL 220RP Z100.

In all applications, the Laser-MIG/MAG process enabled possibilities to obtain significantly increased productivity.

A number of difficulties were also encountered, these are discussed in the report and solutions are suggested.

Aluminium has been welded with deep penetration and high quality at up to 5m/min with a 4 kW laser. Mechanisms for occurrence of porosity have been identified and suggestions about suitable filler materials and welding procedures are given.Superduplex materials can be welded with laser-MIG welding if appropriate filler materials and shielding gases areselected. Process stability is high and near 50 % ratio of ferrite and austenite may be obtained for weldments with high pitting corrosion resistance. DOGAL 600 DP can be welded onto USIBOR 1500 P at high welding speed and good geometric quality of the weldments. Suggestions are given for welding procedures and selections of filler materials and shielding gases. Liquid metal embrittlement of austenitic type stainless steel when welded to zinc coated C-Mn steel was possible to avoid by increasing the ferrite content of the weldments. Duplex type stainless steels have also been demonstrated to be resistant for liquid metal embrittlement when welded to zinc coated C-Mn steels.