The development and production of heat and creep resistant welding consumables for power plant applications are a focus of voestalpine Böhler Welding. Additionally, we support the manufacturers with our far-reaching experience in the welding of creep resistant steels. Fontargen Brazing provides filler metals and fluxes for the brazing in the generators and transformers. voestalpine Böhler Welding produces TUV-approved welding consumables for the base metals most used in thermal power plants. 

The matching filler metals for the creep resistant steels and alloys are tested under creep conditions at elevated temperature. The creep tests have been performed on both all weld metal specimens and weld joints.  

Special steels and special welding consumables are required for highly stressed components such as valves, turbine housing and rotors.. Heavy steel castings and rotor forgings, made of creep resistant steels, play a key role in fossil fuel fired power plants for highly loaded components in the high and intermediate pressure sections of a turbine casting. Turbine and generator rotors withstand high stresses and are the most significant components of a turbine generator system from a safety point of view.

Combinations of different steels are used for the welded rotors. Depending on the operating temperatures, the shafts can be fabricated out of creep resistance material or of highly toughened material.

The welding of low-pressure shafts require matching filler metals. Combined intermediate-low pressure shafts and combined high-low pressure shafts are welded using different steels. These dissimilar welded joints are designed to be located in low stress shaft areas. For this reason, the strength requirements for these welded joints are lower than for the base material. On the other hand, impact energy values of the weldments are even higher than minimum base material values. Creep is not a problem for the low-pressure end of the rotor, but high yield strength, high ductility and low Fracture Appearance Transition Temperature (FATT) behavior is required.

voestalpine Böhler Welding offers tailor-made solutions for the specific customer requirements regarding different steel combinations.

Depending on the application, FGD units require high corrosion resistant steels and Ni-alloys, for tanks, piping, absorbers, etc. The materials selection criteria depend on the chloride and pH concentration. In general, the flue of lignite coal fired power plants is more aggressive than that of hard coal fired power plants. Therefore, the FGDs of a lignite coal fired power plant generally needs high corrosion-resistant Ni-base alloys with increased CPT values.

Depending on the requirements, voestalpine Böhler Welding offers welding consumables higher alloyed than the base material, in order to match the base material corrosion resistance properties compensating the effect of the dilution.