Embrittlement Problems of Metal Structures of Nuclear Power Plants

This paper reports result of the reconstitution of the Cv-type specimens from reactor pressure vessel steel with electron beam welding. Weldability of pressure vessel steel by electron beam welding was investigated in accordance EN ISO 13919-1 standard. There were made investigations of structural changes of metal in welds and heat affected zones to determine influence of welding thermal cycle.(microstructural analysis and microhardness testing of the welds) The welds were inspected using nondestructive testing techniques to determine the quality of the joints. Establishing the optimal reconstitution parameters of electron beam welding process Charpy impact tests show good agreement between original and electron beam reconstituted specimens. The temperature of ductile to brittle transition has been studied. (authors)