Due to possessing high-temperature mechanical properties, high-chromium steels are usually good candidates for harsh environments such as gas-fired powerplants and power generation facilities. These alloys are usually welded using fusion welding processes such as arc welding which produces welded areas of inferior properties. Achieving higher efficiency and lower CO2 emissions requires extending service life of components and use of manufacturing processes with lower CO2 emissions. This CO2 reduction can be amplified if the steel grades are manufactured using greener routes, including more scrap usage.
Now that the European countries are using more renewables for their electricity generation, more flexibility during the operation of thermal powerplants is the key issue. Gas fired powerplants supplement the renewables generation and therefore need to be resistant to thermal cycling as this combined mode of energy generation necessitates much more dynamic operating mode where creep fatigue is the dominant damaging mechanism. This work has looked at a novel solid-state welding, with proven lower CO2 emissions, to address such failure mode and extend the service life of the welded components.
This work is using this approach and proposing a more sustainable process which would enable use of lower quality grades of the same steel for the same application through performance enhancement. This would enable more scrap uptake including scraps of certain harmful tramp elements.