An austenitic stainless steel, which consists of by mass percent, C: not more than 0.02%, Si: not more than 1.5%, Mn: not more than 2%, Cr: 17 to 25%, Ni: 9 to 13%, Cu: more than 0.26% not more than 4%, N: 0.06 to 0.35%, sol. Al: 0.008 to 0.03%. One or more elements selected from Nb, Ti, V, TA, Hf, and Zr in controlled amounts can be included with the balance being Fe and impurities. P, S, Sn, As, Zn, Pb and Sb among the impurities are controlled as P: 0.006 to 0.04%, S: 0.0004 to 0.03%, Sn: 0.001 to 0.1%, As: not more than 0.01%, Zn: not more than 0.01%, Pb: not more than 0.01% and Sb: not more than 0.01%. The amounts of S, P, Sn, As, Zn, Pb and Sb and the amounts of Nb, Ta, Zr, Hf, and Ti are further controlled using formulas.

Austenitic stainless steel

A method to determine corrective actions of a nuclear steam generator, having the steps of modeling of steam generator tube and deposit heat transfer characteristics by analytically deriving specific deposit characteristics and descriptive model parameters, wherein the modeling uses historical thermodynamic data for an operating plant under evaluation, identifying a set of one of preventive and corrective maintenance alternatives to accomplish steam generator deposit objectives, determining through the modeling a power production impact of each of the set of one of preventative and corrective maintenance alternatives to determine an economic cost for each of the set of preventative and corrective maintenance alternatives, and initiating a maintenance alternative with a lowest economic cost as compared to the maintenance evaluation alternatives with higher economic costs.

Method to analyze economics of asset management solutions for nuclear steam generators

This invention provides austenitic steel having a superior resistance to neutron irradiation, a nuclear reactor and a nuclear fission reactor using such steel. In the present invention, austenitic steel containing at least one of Pd and Pt is used for a member which undergoes neutron irradiation in high-temperature water. More specifically, the steel consists essentially of not more than 0.02% C, not more than 1% Si, 0.5-15% Mn, 9-26% Cr, 8-20% Ni, 0.5-3% Mo, at least one kind of 0.1-16% selected from the group consisting of Pd and Pt, and not less than 50% Fe, and may further contain not more than 1.0% of at least one kind selected from the group consisting of Nb, Ti, Zr, Hf and V, and this is used for structural members in a core of a nuclear reactor and a nuclear fission reactor.

Structural member having superior resistance to neutron irradiation embrittlement, austenitic steel for use in same, and use thereof

This heat-resistant austenitic stainless steel has a specific composition containing Ce and Zr and has an Hv 1 /Hv 0 ratio of 1.20 or higher, where Hv 1 is the average hardness of the area ranging from the surface to a thickness-direction depth of 50 μm and Hv 0 is the average hardness of the thickness-direction central part.

Heat-resistant austenitic stainless steel highly inhibited from releasing scale, and stainless-steel pipe

PROBLEM TO BE SOLVED: To provide a Cr-Mn austenitic steel excellent in corrosion resistance, strength, and radiation exposure damage resistance and its production and also to provide a nuclear reactor, a nuclear fusion reactor, and their component parts, by uniformly refining crystalline grain size into superfine state SOLUTION: The Cr-Mn austenitic sintered steel with high corrosion resistance and high strength is a steel containing, by weight, 2 to 15%, and 14-20% Cr and having =90vol% of austenitic phase or a steel further containing, besides the above, at least one kind among <=3% Mo, <=10% Ti, <=20% Zr, and <=10% Nb and having the above characteristics These steels are used for a structure in a nuclear reactor and a part, to be subjected to neutron irradiation and brought into contact with high temp water, of a nuclear fusion furnace, etc

Chromium-manganese austenitic sintered steel with high corrosion resistance and high strength, its production, and its use

PURPOSE: To improve neutron irradiation brittleness resistance under the environment to be in contact with high temp water by constituting at least the surface of a structural member of an austenitic steel having a composition in which respective contents of P and N and the relation between them are specified CONSTITUTION: At least the surface of a structural member used under nuetron irradiation is constituted of an austenitic steel having a composition containing, by weight, <=005% P and <=004% N and satisfying 001%<=P+N<=005% It is desirable that, as to the other components of this austenitic steel, 0002-003% C, 04-06% Si, 05-15% Mn, 9-26% Cr, 8-20% Ni, 01-3% Mo, and <=50% Fe are satisfied Moreover, it is desirable that this stainless steel is allowed to exist in the region between the surface of the structural member and a position at a depth of <=1mm from the surface

Structural member used under neutron irradiation

PURPOSE:To improve the resistance to irradiation brittleness, swelling resistance and stress corrosion resistance in high temp. and high pressure water of apparatus parts to be subjected to neutron irradiation in the core part of a nuclear reactor and a nuclear fusion reactor by manufacturing the apparatus parts with an austenitic stainless steel having specific compsn. CONSTITUTION:The apparatus and structure of the core part subjected to neutron irradiation in a water-boiling reactor, pressurized-water reactor and nuclear fusion reactor are manufactured with a stainless steel having the compsn. contg., by weight, 0.02 to 0.065% C, =50% Fe and having the structure constituted of austenite. The stainless steel has >=1% tensile elongation at the room temp. after the irradiation of electrons of 5X10 n/cm at 300 deg.C, has =0.6 ratio of Cr concn. in grain boundary to Cr concn. in a mother phase, by which the service life of the furnace core member can exceedingly be improved.

Austenitic steel exposed to high temperature and high pressure water under neutron irradiation

PURPOSE:To provide the steel used for nuclear reactor, unclear fusion reactor, etc, by regulating respective contents of Mn, Cr, and Ni so thai Cr concentration in grain boundaries does not practically fall below Cr concentration in a matrix owing to neutron irradiation CONSTITUTION:This austenitic stainless steel is composed of a steel having a composition containing, by weight, <=003% C, <=1% Si, 5-25% Mn, 15-26% Cr, and 10-20% Ni, and the ratio of the atomic volume of Cr to the average atomic volume of the base phase of this steel is regulated to 0900-1030 This steel is prepared in consideration for a phenomenon of the occurrence of Cr- deficient layer in the grain boundaries due to the ejection and diffusion of Cr caused by neutron irradiation and has superior corrosion resistance under a high temp water environment subjected to corpuscular beam irradiation

Austenitic stainless steel excellent in neutron irradiation embrittlement resistance and its use

PURPOSE: To predict the life of a structure by installing a sensor part consisting of a same metal material near a plant structure under a corrosive environment and guiding hydrogen through the sensor part after being generated due to corrosion to the outside of the structure and then measuring the amount of transmission of hydrogen in unit time. CONSTITUTION: A plurality of sensor parts formed by the same metal material as that of a plant structure placed under a corrosive environment is provided in an actual environment near the structure for forming a clearance. Hydrogen which is generated due to corrosion is transmitted through each sensor part and is guided to the outside from the structure. The amount of transmitted hydrogen per unit time is measured for cases where there is clearance and there is no clearance at the sensor part and the hydrogen concentration in metal for the presence or absence of clearance is estimated based on the result. A crack tip hydrogen concentration is obtained from the result and the three-axis stress at the crack tip which is assumed in the structure. The time change of crack length is obtained from the time integration of the sum of the crack progress speed of the same metal under the concentration and the crack progress speed due to corrosion solution and the time when the crack reaches a limit depth is obtained, thus predicting life.

Method and device for predicting life of plant structure

PURPOSE:To enhance the radiation creep resistance of a stainless steel for a spring for pressing each nuclear fuel pellet by adding a little Ti to the steel. CONSTITUTION:A spring for pressing each fuel pellet in a nuclear reactor is manufactured with an austenite stainless steel contg. 0.1-0.15% C, 8.00-10.0% Ni, 17.0-19.0% Cr and 0.15-0.20% Ti. The loss of the elasticity of the spring due to radiation creep is prevented, and the spring can be used for a long time.

Nakada Kiyotomo

Papers

Structural member used under neutron irradiation

Austenitic steel exposed to high temperature and high pressure water under neutron irradiation

Austenitic stainless steel excellent in neutron irradiation embrittlement resistance and its use

Method and device for predicting life of plant structure

Austenite stainless steel for spring for nuclear fuel