The combination of good corrosion resistance, high strength and good ductility make duplex stainless steel 1.4462 (UNS S 31803) an ideal candidate material for the construction of cargo tanks of chemical tank vessels. Light weight structures can be realised improving the profitability of the ship. The option to use sea water for cleaning purposes and ballast loads is an additional asset. An outlook into the application of simultaneous laser beam welding, a modern manufacturing process with high productivity, is given. By using this process weld joints with excellent mechanical and corrosion properties without post weld heat treatment are obtained at a very high welding speed.