Application of high nickel alloys in the field of experience within corrosion resistance protection in flue gas desulphurization plants absorbers

Absorbers are the main components of flue gas desulphurization plants for 360 MW power-generating units in Belchatow Power Plant. The whole plant operating cycle and its service life depend on the type of materials applied for corrosion resistance lining of various absorber zones. RAFAKO S.A. activities within this field are focused on the extension of FGD plant service life via implementation of technology of lining the cylindrical part of absorber with 0,5 - 1,6 mm thickness sheets made of Hastelloy type alloys of C-22 and C-2000 grade. The experiment carried out on Hastelloy C-22 and C-2000 alloy grades enabled the assessment of corrosion resistance properties of base material, lining plates, weld joints and HAZ. The paper contains the results of weld joints and HAZ structure assessment, weld joints corrosion resistance characteristics, results of corrosion products examinations as well as requirements and recommendations concerning the execution of weld joints, lining steel surface preparation for welding, etc. (authors)