Korea Atomic Energy Research Institute

Dae-Whan Kim

Sung-Soo Kim

Young-Suk Kim

Joon-Wha Hong

Young-Whan Kang

Seong-Su Kim

The disclose relates to ordered Alloy 690 comprising: a matrix that includes a short range order (SRO) in a state in which nickel (Ni) is enriched, and chromium (Cr) and iron (Fe) are depleted, and the ordered Alloy 690 is characterized by having excellent resistance to stress corrosion cracking and improved thermal conductivity due to agglomeration of nickel (Ni) atoms, as compared with the unordered Alloy 690.

Ordered alloy 690 with improved thermal conductivity

The present invention relates to a method for manufacturing Alloy 690 ordered alloy to be used in a steam generator tube serving as a heat exchanger in a nuclear power plant (hereinafter, referred to as NPP), and Alloy 690 ordered alloy manufactured thereby, and provides a method for manufacturing Alloy 690 ordered alloy with improved thermal conductivity, and Alloy 690 ordered alloy manufactured thereby, the method comprising the steps of: solution-annealing Alloy 690; cooling the solution-annealed Alloy 690 to a first temperature of 200&#xb0; C./min or less; and ordering the cooled Alloy 690 in the temperature range of 410-520&#xb0; C.

Method for manufacturing alloy 690 ordered alloy with improved thermal conductivity, and alloy 690 ordered alloy manufactured thereby

The present invention relates to ordered Alloy 690 with improved thermal conductivity. By maintaining Alloy 690 in a temperature range of 350-570&#xb0; C. for a proper amount of time, the atomic arrangement is controlled to properly form the ordered phases. The ordered phases formed in the ordered Alloy 690 increases its thermal conductivity due to a low thermal scattering effect of the ordered phase as observed in pure metals.

Production method for alloy 690 ordered alloy of improved thermal conductivity, and alloy 690 ordered alloy produced thereby

A method of non-destructive evaluation of stress corrosion cracking of structural components made of metal alloys, and a method of evaluation of the remaining lifetime of the structural component made of metal alloys are provided, in which a change in properties of the structural components made of metal alloys being used in operating nuclear power plants is measured according to the degree of atomic ordering (or short range ordering) of alloying atoms, and stress corrosion cracking of the structural components made of metal alloys is thus evaluated. The properties to be measured may be one or more selected from a group consisting of hardness, electrical resistivity and thermal conductivity.

Method of non-destructive evaluation of intergranular stress corrosion cracking (IGSSC) in structural components made of metal alloys, and the method of lifetime evaluation of the structural components

A method for manufacturing a delayed hydride cracking resistant zirconium ahoy (Zircaloy-2, Zircaloy-4, Zr-2.5% Nb, pure Zr, etc.) pressure tube includes the steps of making a seamless pressure tube having a diameter smaller than the final size by extrusion or drawing, and then expanding the tube at a temperature below 600.degree. C. by cross rolling.

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Daejeon, South Korea

Dae-Whan Kim