XHM-1 ALLOY AS A PROMISING STRUCTURAL MATERIAL FOR WATER-COOLED FUSION-REACTOR COMPONENTS

Experience gained in utilizing austenitic stainless steel components i n water-cooled power reactors indicates that the main cause of their f ailure is the steel's propensity for corrosion cracking, In search of a material immune to this type of corrosion, different types of austen itic steels and chromium-nickel alloys were investigated and tested at VNIINM. This paper presents the results of studying physical and mech anical properties, irradiation and corrosion resistance in a water coo lant at < 350 degrees C of the alloy XHM-1 as compared with austenitic stainless steels 00Cr16Ni15Mo3Nb, 00Cr20Ni25Nb and alloy 00Cr20Ni40Mo 5Nb. Analysis of the results shows that, as distinct from the stainles s steels studied, the XHM-1 alloy is completely immune to corrosion cr acking (CC). Not a single induced damage was encountered within 50 to 350 degrees C in water containing different amounts of chlorides and o xygen under tensile stresses up to the yield strength of the material. One more distinctive feature of the alloy compared to steels is that no change in the strength or total elongation is encountered in the al loy specimens irradiated to 32 dpa at 350 degrees C. The XHM-1 alloy h as adequate fabricability and high weldability characteristics. As far as its properties are concerned, the XHM-1 alloy is very promising as a material for water-cooled fusion reactor components.