Properties of Thickwelded Similar and Dissimilar Joints Made of Tempaloy A-3 Steel Assigned for Power Industry

A continuous trend aimed to reduce pollutant emissions to atmosphere and  lower power generation costs is directly related to increasing efficiency of power units in conventional power stations. An increase in efficiency is obtained through boosting key working parameters i.e. steam pressure and temperature. The steam parameters in the new high efficiency fossil fuel power plants are continuously increasing, using new advanced materials with enhanced creep strength able to operate on the most severe temperature and pressure conditions. In this publication authors presents the results of nondestructive (RT, VT) and destructive (tensile test, bending test, hardness measurements, impact strength, macro- and micrograph) test. The major objective of those examination was to check properties of welded joints made from similar joint made of Tempaloy A-3 steel and disimilar joints of Tempaloy A-3 + P91. Positive results of examination of disimilar joints shows that there is possibility to put this combination in to practise in power engineering industry. Accoding to this boiler parts made of two different materials can afford higher working parameters (pressure and temperature) than made just from one type of steel - P91. Examination of disimilar welded joint were performed in Institute of Welding in Gliwice and they are one of the first positive results for this combination in the world. There where no future investigation made by welding dissimilar joints of Tmapaloy A-3 + P91 steel grades. The results of this investigation shows that there is a possibility to integrate Tempaloy A-3 steel into parts of powerplants instalation with P91 steel grates.