Low alloy steels are essential for the construction of power plants and are normally employed for temperatures up to about 550°C. They are normally used for fabrication of critical components such water walls, superheaters, reheaters and piping. In new power plants these materials represent important fraction of all materials employed and therefore significant effort has been invested to improve their characteristics, in particular creep strength, ductility and weldability. Grade 23 is one of the most successful results of such development. Its balanced alloying (0.07C- 2.25Cr-1.5W-V-Nb) has increased significantly the creep resistance in comparison to grade 22, yet permitting to skip the PWHT on thin sections. With the aim to develop the weld metal for the grade 23 in particular, leading European industries, research centres and utilities have joined effort within the EU project ALoAS to achieve this target. The effect of the chemical composition of SMAW and SAW consumables on creep, ductility and long term stability of welded joints has been investigated. This has required a thorough characterization of the microstructures of the base materials and welded joints, as well as of the long term properties at high temperatures. The results are presented and discussed on weld metal development, microstructural stability and the methodology to evaluate the suitability of the consumables for the actual applications.
|Title of host publication||Creep 2008, 11th International Conference on Creep and Fracture of engineering Materials and Structures, 4-9 May 2008, Bayreuth, Germany|
|Publication status||Published - 2008|
|MoE publication type||A4 Article in a conference publication|
|Event||11th International Conference of Creep and Fracture of Engineering Materials and Structures, CREEP 2008 - Bad Berneck, Germany|
Duration: 4 May 2008 → 9 May 2008
|Conference||11th International Conference of Creep and Fracture of Engineering Materials and Structures, CREEP 2008|
|Period||4/05/08 → 9/05/08|