Abstract: A method for reducing in situ the electrochemical corrosion potential and susceptibility to stress corrosion cracking of a nickel-base alloy and boiling water nuclear reactor components formed therefrom when in contact with high temperature water. The method comprises the steps of: adding a metal hydride to the high temperature water; dissociating the metal hydride in the high temperature water to form a metal and at least one hydrogen ion; and reducing the concentration of the oxidizing species by reacting the hydrogen ions with an oxidizing species, thereby reducing in situ the electrochemical corrosion potential of the nickel-base alloy. The method may further include the steps of reacting the metal with oxygen present in the high temperature water to form an insoluble oxide and incorporating the metal into the surface of the nickel-base alloy, thereby reducing the electrical conductivity of the surface of the nickel-base alloy.

Abstract: An article, such as a turbine engine component, formed from a nickel-base superalloy, the nickel-base superalloy containing a &ggr;″ tetragonal phase and comprising aluminum, titanium, tantalum, niobium, chromium, molybdenum, and the balance nickel, wherein the article has a time dependent crack propagation resistance of at least about 20 hours to failure at about 1100° F. in the presence of steam. The invention also includes a nickel-base superalloy for forming such and article and methods of forming the article and making the nickel-base superalloy.

Abstract: A method for detecting whether a natural diamond has been processed at high pressure and high temperature (HPHT) conditions comprises steps of disposing the diamond in a cyrostat that is provided at temperatures equal to or less than liquid nitrogen; illuminating the diamond with a laser beam; recording an optical spectrum of the diamond with a photoluminescence spectrometer; and examining the optical spectrum of the diamond to detect an absence of selected photoluminescent spectral lines.