Laser hybrid welding of a lean duplex stainless steel

Abstract

The use of duplex stainless steel increases steadily worldwide and the fluctuations in nickel price the recent years have contributed to further growth. The lean duplex grade Outokumpu LDX 2101 (EN 1.4162, UNS S32101) has low nickel content and is alloyed with nitrogen and manganese to give a balanced microstructure. It means that good austenite formation is obtained even when laser welding autogenously (without filler). This is in contrast to most other duplex grades, for which laser welding is normally associated with high ferrite fractions known to reduce the ductility and corrosion performance. Laser welding of LDX 2101 has been performed with and without filler wire, and laser hybrid welding with gas tungsten arc (GTA) and gas metal arc (GMA) using Nd:YAG, CO2 and fiber lasers. The microstructure is evaluated and compared with the corrosion performance, and the mechanical properties are presented.The use of duplex stainless steel increases steadily worldwide and the fluctuations in nickel price the recent years have contributed to further growth. The lean duplex grade Outokumpu LDX 2101 (EN 1.4162, UNS S32101) has low nickel content and is alloyed with nitrogen and manganese to give a balanced microstructure. It means that good austenite formation is obtained even when laser welding autogenously (without filler). This is in contrast to most other duplex grades, for which laser welding is normally associated with high ferrite fractions known to reduce the ductility and corrosion performance. Laser welding of LDX 2101 has been performed with and without filler wire, and laser hybrid welding with gas tungsten arc (GTA) and gas metal arc (GMA) using Nd:YAG, CO2 and fiber lasers. The microstructure is evaluated and compared with the corrosion performance, and the mechanical properties are presented.