Abstract: A fastening member in an embodiment consists of a bolt and a nut. A hard layer made of a metal nitride is formed on a surface of a threaded portion of the bolt or a surface of a threaded portion of the nut.

Abstract: According to one embodiment, a blade damage evaluation system comprising one or more computers configured to: evaluate inflow and collision of solid particles into a turbine based on design data, maintenance data, and operation data; and calculate a survival rate by applying at least one data included in at least one of the design data, the maintenance data, and the operation data as at least one factor to a formula that models the turbine by survival time analysis, the survival rate indicating that erosion amount of at least one of a plurality of blades does not reach a predetermined threshold at arbitrary time in future.

Abstract: A blade damage evaluation apparatus includes: a registration unit for design information of a turbine and maintenance information; an acquisition processor for detection data of sensors; a first discrimination processor for first facility states of the turbine at a plurality of past time points; a classification processor for classes Cn of a plurality of first facility states; a first determination processor for first operating state values of the turbine; another registration unit for first damage rates at past time points; a setting processor of a characteristic function for each of the classes Cn; a second discrimination processor for a second facility state of the turbine at the current time point; a second determination processor for a second operating state value of the turbine at the current time point; and an analyzer for a second damage rate at the current time point.

Abstract: A blade damage evaluation apparatus includes: a registration unit for design information of a turbine and maintenance information; an acquisition processor for detection data of sensors; a first discrimination processor for first facility states of the turbine at a plurality of past time points; a classification processor for classes Cn of a plurality of first facility states; a first determination processor for first operating state values of the turbine; another registration unit for first damage rates at past time points; a setting processor of a characteristic function for each of the classes Cn; a second discrimination processor for a second facility state of the turbine at the current time point; a second determination processor for a second operating state value of the turbine at the current time point; and an analyzer for a second damage rate at the current time point.

Abstract: A welding method, which subjects a surface to be built-up of an elongated workpiece to a build-up welding process along a longitudinal direction of the workpiece, includes a step for forming a build-up layer on the surface to be built-up by supplying a filler metal to the surface to be built-up along the longitudinal direction and by applying a laser beam thereto to melt the filler metal. A refrigerant is supplied to the surface to be built-up of the workpiece, during the step for forming the build-up layer.

Abstract: A welding method for subjecting a surface to be built-up of an elongated workpiece to a build-up welding process along a longitudinal direction of the workpiece, the welding method includes a step of forming a build-up layer on the surface to be built-up by supplying a filler metal to the surface to be built-up along the longitudinal direction and by applying a laser beam thereto to melt the filler metal. In the step of forming the build-up layer, information on a dimension of a molten pool formed by the filler metal and the workpiece molten by the laser beam is obtained, and an output of the laser beam is controlled based on the information.