Influence of Nickel on the Properties of P91 Flux Cored Wire Weld Metal

The creep strength enhanced steel P91 has been used in thermal power plants since the 1990s. As flux cored wires for gas metal arc welding offer several technical and economic advantages, they become more and more popular and also matching flux cored wires for welding P91 have been available for several years. Nickel is often added to filler metals to increase the toughness of the weld metal at room temperature. However, the requirement of Mn + Ni < 1.0 wt% forced the modification of the flux cored wire weld metal. In this contribution, the influence of reduced Ni-content on the mechanical properties at ambient temperature and on creep properties is presented. It confirms that an elevated Ni-content is not necessary to meet the toughness requirements of AWS A5.36.