Abstract: A thermal barrier coating (100) includes a heat-resistant alloy substrate which is used in a turbine member and a ceramic layer (300) which is formed on the heat-resistant alloy substrate and in which vertical cracks (C) extending in a thickness direction are dispersed in a surface direction and a plurality of pores (P) are included on the inside. Thermal spray particles composed of YbSZ having a particle-size distribution in which a 50% particle diameter in a cumulative particle-size distribution is 40 ?m to 100 ?m are thermally sprayed at a thermal spray distance of 80 mm or less, the vertical cracks (C) are dispersed at a pitch of 0.5 cracks/mm to 40 cracks/mm in the surface direction, and the ceramic layer (300) of which a porosity attributable to the vertical cracks (C) and the pores (P) combined is 4% to 15% is formed.

Abstract: The present invention provides a production method for thermal spray particles forming a ceramic layer in which vertical cracks extending in a thickness direction are dispersed in a surface direction and which includes a plurality of pores inside. The production method for thermal spray particles includes adjusting a solid content concentration of slurry (13) to 75 wt % to 85 wt %, supplying the slurry (13) to a disk-shaped atomizer (12) of a spray drying device (10), setting a protrusion speed at which the slurry (13) protrudes from the atomizer (12) to 60 m/second to 90 m/second. and performing a heat treatment on thermal spray particle bodies (22) formed by drying the slurry (13) to produce thermal spray particles composed of YbSZ in which a 50% particle diameter in a cumulative particle-size distribution is 40 ?m to 100 ?m.

Abstract: A turbine rotor blade repair method which reduces the occurrence of cracks due to welding is provided. A turbine rotor blade repair method for repairing damage of a fin at a tip of a turbine rotor blade includes overlaying a damaged portion of the fin with metal by welding (step S2); peening on a boundary region between the fin and the overlaying metal (step S4); and after the peening, performing solution treatment to repair the damage of the fin of the turbine rotor blade (step S6).

Abstract: A bolt has a male screw with a surface hardening portion that has an increased surface hardness and that is applied with a compressive residual stress. The male screw is formed by cutting the bolt, and performing a process to provide at least on the surface of the male screw of the bolt the surface hardening portion that has increased hardness and that is applied with a compressive residual stress. As a result, the fatigue resistance of the male screw is improved and the bolt is effective for use in a portion where the male screw is subject to a repetitive stress.

Abstract: A bolt has a male screw with a surface hardening portion that has an increased surface hardness and that is applied with a compressive residual stress. The male screw is formed by cutting the bolt, and performing a process to provide at least on the surface of the male screw of the bolt the surface hardening portion that has increased hardness and that is applied with a compressive residual stress. As a result, the fatigue resistance of the male screw is improved and the bolt is effective for use in a portion where the male screw is subject to a repetitive stress.

Abstract: A turbine rotor blade repair method which reduces the occurrence of cracks due to welding is provided. A turbine rotor blade repair method for repairing damage of a fin at a tip of a turbine rotor blade includes overlaying a damaged portion of the fin with metal by welding (step S2); peening on a boundary region between the fin and the overlaying metal (step S4); and after the peening, performing solution treatment to repair the damage of the fin of the turbine rotor blade (step S6).

Abstract: The present invention provides a surface hardening portion 11 that has increased surface hardness and that is applied with a compressive residual stress, at least on the surface of a male screw 10 of a bolt 1. The present invention includes the steps of cutting to form the male screw 10 of the bolt 1, and processing to provide at least on the surface of the male screw 10 of the bolt 1 the surface hardening portion 11 that has increased hardness and that is applied with a compressive residual stress. As a result, the present invention can improve the fatigue resistance of the male screw 10 and the bolt is effective as a bolt to be used in a portion where the male screw 10 is subject to a repetitive stress.